90 files changed, 2479 insertions, 795 deletions

diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index 32c7cf7ef..ae9dccce9 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -13,6 +13,7 @@ env:
   CARGO_NET_RETRY: 10
   RUSTFLAGS: "-D warnings -W unreachable-pub"
   RUSTUP_MAX_RETRIES: 10
+  FETCH_DEPTH: 200
 
 jobs:
   dist-x86_64-pc-windows-msvc:
@@ -24,6 +25,8 @@ jobs:
     steps:
     - name: Checkout repository
       uses: actions/checkout@v2
+      with:
+        fetch-depth: ${{ env.FETCH_DEPTH }}
 
     # We need to disable the existing toolchain to avoid updating rust-docs
     # which takes a long time. The fastest way to do this is to rename the
@@ -57,6 +60,8 @@ jobs:
     steps:
     - name: Checkout repository
       uses: actions/checkout@v2
+      with:
+        fetch-depth: ${{ env.FETCH_DEPTH }}
 
     - name: Rename existing rust toolchain
       run: Rename-Item C:\Users\runneradmin\.rustup\toolchains\stable-x86_64-pc-windows-msvc C:\Users\runneradmin\.rustup\toolchains\stable-x86_64-pc-windows-msvc.old
@@ -87,6 +92,8 @@ jobs:
     steps:
     - name: Checkout repository
       uses: actions/checkout@v2
+      with:
+        fetch-depth: ${{ env.FETCH_DEPTH }}
 
     - name: Install Rust toolchain
       uses: actions-rs/toolchain@v1
@@ -139,6 +146,8 @@ jobs:
 
     - name: Checkout repository
       uses: actions/checkout@v2
+      with:
+        fetch-depth: ${{ env.FETCH_DEPTH }}
 
     - name: Dist
       run: cargo xtask dist
@@ -159,6 +168,8 @@ jobs:
     steps:
     - name: Checkout repository
       uses: actions/checkout@v2
+      with:
+        fetch-depth: ${{ env.FETCH_DEPTH }}
 
     - name: Install Rust toolchain
       uses: actions-rs/toolchain@v1
@@ -193,6 +204,8 @@ jobs:
 
     - name: Checkout repository
       uses: actions/checkout@v2
+      with:
+        fetch-depth: ${{ env.FETCH_DEPTH }}
 
     - name: Install Rust toolchain
       uses: actions-rs/toolchain@v1
@@ -223,6 +236,8 @@ jobs:
 
     - name: Checkout repository
       uses: actions/checkout@v2
+      with:
+        fetch-depth: ${{ env.FETCH_DEPTH }}
 
     - name: Install Rust toolchain
       uses: actions-rs/toolchain@v1
@@ -259,6 +274,8 @@ jobs:
 
     - name: Checkout repository
       uses: actions/checkout@v2
+      with:
+        fetch-depth: ${{ env.FETCH_DEPTH }}
 
     - run: echo "HEAD_SHA=$(git rev-parse HEAD)" >> $GITHUB_ENV
     - run: 'echo "HEAD_SHA: $HEAD_SHA"'
diff --git a/Cargo.lock b/Cargo.lock
index b1fef2e80..b99c243a4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,7 +1,5 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
-
 [[package]]
 name = "addr2line"
 version = "0.14.1"
@@ -486,6 +484,7 @@ dependencies = [
  "log",
  "profile",
  "rustc-hash",
+ "smallvec",
  "stdx",
  "syntax",
  "tt",
@@ -1325,9 +1324,9 @@ checksum = "b5eb417147ba9860a96cfe72a0b93bf88fee1744b5636ec99ab20c1aa9376581"
 
 [[package]]
 name = "rowan"
-version = "0.12.6"
+version = "0.13.0-pre.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1b36e449f3702f3b0c821411db1cbdf30fb451726a9456dce5dabcd44420043"
+checksum = "8f300be7fa17c3fa563d2bc6ab5b1a8d5163162f9111599eda4f86a563714724"
 dependencies = [
  "countme",
  "hashbrown",
@@ -1810,9 +1809,9 @@ checksum = "56dee185309b50d1f11bfedef0fe6d036842e3fb77413abef29f8f8d1c5d4c1c"
 
 [[package]]
 name = "ungrammar"
-version = "1.11.0"
+version = "1.12.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "84c629795d377049f2a1dc5f42cf505dc5ba8b28a5df0a03f4183a24480e4a6a"
+checksum = "df6586a7c530704efe803d49a0b4132dcbdb4063163df39110548e6b5f2373ba"
 
 [[package]]
 name = "unicase"
diff --git a/crates/hir/Cargo.toml b/crates/hir/Cargo.toml
index d4ea7327e..55e9c3f0c 100644
--- a/crates/hir/Cargo.toml
+++ b/crates/hir/Cargo.toml
@@ -15,6 +15,7 @@ rustc-hash = "1.1.0"
 either = "1.5.3"
 arrayvec = "0.5.1"
 itertools = "0.10.0"
+smallvec = "1.4.0"
 
 stdx = { path = "../stdx", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
diff --git a/crates/hir/src/display.rs b/crates/hir/src/display.rs
new file mode 100644
index 000000000..44cdcc296
--- /dev/null
+++ b/crates/hir/src/display.rs
@@ -0,0 +1,441 @@
+//! HirDisplay implementations for various hir types.
+use hir_def::{
+    adt::VariantData,
+    generics::{TypeParamProvenance, WherePredicate, WherePredicateTypeTarget},
+    type_ref::{TypeBound, TypeRef},
+    AdtId, GenericDefId,
+};
+use hir_ty::display::{
+    write_bounds_like_dyn_trait_with_prefix, write_visibility, HirDisplay, HirDisplayError,
+    HirFormatter,
+};
+use syntax::ast::{self, NameOwner};
+
+use crate::{
+    Const, ConstParam, Enum, Field, Function, HasVisibility, Module, Static, Struct, Substs, Trait,
+    Type, TypeAlias, TypeParam, Union, Variant,
+};
+
+impl HirDisplay for Function {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        let data = f.db.function_data(self.id);
+        write_visibility(self.module(f.db).id, self.visibility(f.db), f)?;
+        let qual = &data.qualifier;
+        if qual.is_default {
+            write!(f, "default ")?;
+        }
+        if qual.is_const {
+            write!(f, "const ")?;
+        }
+        if qual.is_async {
+            write!(f, "async ")?;
+        }
+        if qual.is_unsafe {
+            write!(f, "unsafe ")?;
+        }
+        if let Some(abi) = &qual.abi {
+            // FIXME: String escape?
+            write!(f, "extern \"{}\" ", abi)?;
+        }
+        write!(f, "fn {}", data.name)?;
+
+        write_generic_params(GenericDefId::FunctionId(self.id), f)?;
+
+        write!(f, "(")?;
+
+        let write_self_param = |ty: &TypeRef, f: &mut HirFormatter| match ty {
+            TypeRef::Path(p) if p.is_self_type() => write!(f, "self"),
+            TypeRef::Reference(inner, lifetime, mut_) if matches!(&**inner,TypeRef::Path(p) if p.is_self_type()) =>
+            {
+                write!(f, "&")?;
+                if let Some(lifetime) = lifetime {
+                    write!(f, "{} ", lifetime.name)?;
+                }
+                if let hir_def::type_ref::Mutability::Mut = mut_ {
+                    write!(f, "mut ")?;
+                }
+                write!(f, "self")
+            }
+            _ => {
+                write!(f, "self: ")?;
+                ty.hir_fmt(f)
+            }
+        };
+
+        let mut first = true;
+        for (param, type_ref) in self.assoc_fn_params(f.db).into_iter().zip(&data.params) {
+            if !first {
+                write!(f, ", ")?;
+            } else {
+                first = false;
+                if data.has_self_param {
+                    write_self_param(type_ref, f)?;
+                    continue;
+                }
+            }
+            match param.pattern_source(f.db) {
+                Some(ast::Pat::IdentPat(p)) if p.name().is_some() => {
+                    write!(f, "{}: ", p.name().unwrap())?
+                }
+                _ => write!(f, "_: ")?,
+            }
+            // FIXME: Use resolved `param.ty` or raw `type_ref`?
+            // The former will ignore lifetime arguments currently.
+            type_ref.hir_fmt(f)?;
+        }
+        write!(f, ")")?;
+
+        // `FunctionData::ret_type` will be `::core::future::Future<Output = ...>` for async fns.
+        // Use ugly pattern match to strip the Future trait.
+        // Better way?
+        let ret_type = if !qual.is_async {
+            &data.ret_type
+        } else {
+            match &data.ret_type {
+                TypeRef::ImplTrait(bounds) => match &bounds[0] {
+                    TypeBound::Path(path) => {
+                        path.segments().iter().last().unwrap().args_and_bindings.unwrap().bindings
+                            [0]
+                        .type_ref
+                        .as_ref()
+                        .unwrap()
+                    }
+                    _ => panic!("Async fn ret_type should be impl Future"),
+                },
+                _ => panic!("Async fn ret_type should be impl Future"),
+            }
+        };
+
+        match ret_type {
+            TypeRef::Tuple(tup) if tup.is_empty() => {}
+            ty => {
+                write!(f, " -> ")?;
+                ty.hir_fmt(f)?;
+            }
+        }
+
+        write_where_clause(GenericDefId::FunctionId(self.id), f)?;
+
+        Ok(())
+    }
+}
+
+impl HirDisplay for Struct {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write_visibility(self.module(f.db).id, self.visibility(f.db), f)?;
+        write!(f, "struct ")?;
+        write!(f, "{}", self.name(f.db))?;
+        let def_id = GenericDefId::AdtId(AdtId::StructId(self.id));
+        write_generic_params(def_id, f)?;
+        write_where_clause(def_id, f)?;
+        Ok(())
+    }
+}
+
+impl HirDisplay for Enum {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write_visibility(self.module(f.db).id, self.visibility(f.db), f)?;
+        write!(f, "enum ")?;
+        write!(f, "{}", self.name(f.db))?;
+        let def_id = GenericDefId::AdtId(AdtId::EnumId(self.id));
+        write_generic_params(def_id, f)?;
+        write_where_clause(def_id, f)?;
+        Ok(())
+    }
+}
+
+impl HirDisplay for Union {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write_visibility(self.module(f.db).id, self.visibility(f.db), f)?;
+        write!(f, "union ")?;
+        write!(f, "{}", self.name(f.db))?;
+        let def_id = GenericDefId::AdtId(AdtId::UnionId(self.id));
+        write_generic_params(def_id, f)?;
+        write_where_clause(def_id, f)?;
+        Ok(())
+    }
+}
+
+impl HirDisplay for Field {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write_visibility(self.parent.module(f.db).id, self.visibility(f.db), f)?;
+        write!(f, "{}: ", self.name(f.db))?;
+        self.signature_ty(f.db).hir_fmt(f)
+    }
+}
+
+impl HirDisplay for Variant {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write!(f, "{}", self.name(f.db))?;
+        let data = self.variant_data(f.db);
+        match &*data {
+            VariantData::Unit => {}
+            VariantData::Tuple(fields) => {
+                write!(f, "(")?;
+                let mut first = true;
+                for (_, field) in fields.iter() {
+                    if first {
+                        first = false;
+                    } else {
+                        write!(f, ", ")?;
+                    }
+                    // Enum variant fields must be pub.
+                    field.type_ref.hir_fmt(f)?;
+                }
+                write!(f, ")")?;
+            }
+            VariantData::Record(fields) => {
+                write!(f, " {{")?;
+                let mut first = true;
+                for (_, field) in fields.iter() {
+                    if first {
+                        first = false;
+                        write!(f, " ")?;
+                    } else {
+                        write!(f, ", ")?;
+                    }
+                    // Enum variant fields must be pub.
+                    write!(f, "{}: ", field.name)?;
+                    field.type_ref.hir_fmt(f)?;
+                }
+                write!(f, " }}")?;
+            }
+        }
+        Ok(())
+    }
+}
+
+impl HirDisplay for Type {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        self.ty.value.hir_fmt(f)
+    }
+}
+
+impl HirDisplay for TypeParam {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write!(f, "{}", self.name(f.db))?;
+        let bounds = f.db.generic_predicates_for_param(self.id);
+        let substs = Substs::type_params(f.db, self.id.parent);
+        let predicates = bounds.iter().cloned().map(|b| b.subst(&substs)).collect::<Vec<_>>();
+        if !(predicates.is_empty() || f.omit_verbose_types()) {
+            write_bounds_like_dyn_trait_with_prefix(":", &predicates, f)?;
+        }
+        Ok(())
+    }
+}
+
+impl HirDisplay for ConstParam {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write!(f, "const {}: ", self.name(f.db))?;
+        self.ty(f.db).hir_fmt(f)
+    }
+}
+
+fn write_generic_params(def: GenericDefId, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+    let params = f.db.generic_params(def);
+    if params.lifetimes.is_empty()
+        && params.consts.is_empty()
+        && params
+            .types
+            .iter()
+            .all(|(_, param)| !matches!(param.provenance, TypeParamProvenance::TypeParamList))
+    {
+        return Ok(());
+    }
+    write!(f, "<")?;
+
+    let mut first = true;
+    let mut delim = |f: &mut HirFormatter| {
+        if first {
+            first = false;
+            Ok(())
+        } else {
+            write!(f, ", ")
+        }
+    };
+    for (_, lifetime) in params.lifetimes.iter() {
+        delim(f)?;
+        write!(f, "{}", lifetime.name)?;
+    }
+    for (_, ty) in params.types.iter() {
+        if ty.provenance != TypeParamProvenance::TypeParamList {
+            continue;
+        }
+        if let Some(name) = &ty.name {
+            delim(f)?;
+            write!(f, "{}", name)?;
+            if let Some(default) = &ty.default {
+                write!(f, " = ")?;
+                default.hir_fmt(f)?;
+            }
+        }
+    }
+    for (_, konst) in params.consts.iter() {
+        delim(f)?;
+        write!(f, "const {}: ", konst.name)?;
+        konst.ty.hir_fmt(f)?;
+    }
+
+    write!(f, ">")?;
+    Ok(())
+}
+
+fn write_where_clause(def: GenericDefId, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+    let params = f.db.generic_params(def);
+    if params.where_predicates.is_empty() {
+        return Ok(());
+    }
+
+    let write_target = |target: &WherePredicateTypeTarget, f: &mut HirFormatter| match target {
+        WherePredicateTypeTarget::TypeRef(ty) => ty.hir_fmt(f),
+        WherePredicateTypeTarget::TypeParam(id) => match &params.types[*id].name {
+            Some(name) => write!(f, "{}", name),
+            None => write!(f, "{{unnamed}}"),
+        },
+    };
+
+    write!(f, "\nwhere")?;
+
+    for (pred_idx, pred) in params.where_predicates.iter().enumerate() {
+        let prev_pred =
+            if pred_idx == 0 { None } else { Some(&params.where_predicates[pred_idx - 1]) };
+
+        let new_predicate = |f: &mut HirFormatter| {
+            write!(f, "{}", if pred_idx == 0 { "\n    " } else { ",\n    " })
+        };
+
+        match pred {
+            WherePredicate::TypeBound { target, bound } => {
+                if matches!(prev_pred, Some(WherePredicate::TypeBound { target: target_, .. }) if target_ == target)
+                {
+                    write!(f, " + ")?;
+                } else {
+                    new_predicate(f)?;
+                    write_target(target, f)?;
+                    write!(f, ": ")?;
+                }
+                bound.hir_fmt(f)?;
+            }
+            WherePredicate::Lifetime { target, bound } => {
+                if matches!(prev_pred, Some(WherePredicate::Lifetime { target: target_, .. }) if target_ == target)
+                {
+                    write!(f, " + {}", bound.name)?;
+                } else {
+                    new_predicate(f)?;
+                    write!(f, "{}: {}", target.name, bound.name)?;
+                }
+            }
+            WherePredicate::ForLifetime { lifetimes, target, bound } => {
+                if matches!(
+                    prev_pred,
+                    Some(WherePredicate::ForLifetime { lifetimes: lifetimes_, target: target_, .. })
+                    if lifetimes_ == lifetimes && target_ == target,
+                ) {
+                    write!(f, " + ")?;
+                } else {
+                    new_predicate(f)?;
+                    write!(f, "for<")?;
+                    for (idx, lifetime) in lifetimes.iter().enumerate() {
+                        if idx != 0 {
+                            write!(f, ", ")?;
+                        }
+                        write!(f, "{}", lifetime)?;
+                    }
+                    write!(f, "> ")?;
+                    write_target(target, f)?;
+                    write!(f, ": ")?;
+                }
+                bound.hir_fmt(f)?;
+            }
+        }
+    }
+
+    // End of final predicate. There must be at least one predicate here.
+    write!(f, ",")?;
+
+    Ok(())
+}
+
+impl HirDisplay for Const {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write_visibility(self.module(f.db).id, self.visibility(f.db), f)?;
+        let data = f.db.const_data(self.id);
+        write!(f, "const ")?;
+        match &data.name {
+            Some(name) => write!(f, "{}: ", name)?,
+            None => write!(f, "_: ")?,
+        }
+        data.type_ref.hir_fmt(f)?;
+        Ok(())
+    }
+}
+
+impl HirDisplay for Static {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write_visibility(self.module(f.db).id, self.visibility(f.db), f)?;
+        let data = f.db.static_data(self.id);
+        write!(f, "static ")?;
+        if data.mutable {
+            write!(f, "mut ")?;
+        }
+        match &data.name {
+            Some(name) => write!(f, "{}: ", name)?,
+            None => write!(f, "_: ")?,
+        }
+        data.type_ref.hir_fmt(f)?;
+        Ok(())
+    }
+}
+
+impl HirDisplay for Trait {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write_visibility(self.module(f.db).id, self.visibility(f.db), f)?;
+        let data = f.db.trait_data(self.id);
+        if data.is_unsafe {
+            write!(f, "unsafe ")?;
+        }
+        if data.is_auto {
+            write!(f, "auto ")?;
+        }
+        write!(f, "trait {}", data.name)?;
+        let def_id = GenericDefId::TraitId(self.id);
+        write_generic_params(def_id, f)?;
+        if !data.bounds.is_empty() {
+            write!(f, ": ")?;
+            f.write_joined(&*data.bounds, " + ")?;
+        }
+        write_where_clause(def_id, f)?;
+        Ok(())
+    }
+}
+
+impl HirDisplay for TypeAlias {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write_visibility(self.module(f.db).id, self.visibility(f.db), f)?;
+        let data = f.db.type_alias_data(self.id);
+        write!(f, "type {}", data.name)?;
+        if !data.bounds.is_empty() {
+            write!(f, ": ")?;
+            f.write_joined(&data.bounds, " + ")?;
+        }
+        if let Some(ty) = &data.type_ref {
+            write!(f, " = ")?;
+            ty.hir_fmt(f)?;
+        }
+        Ok(())
+    }
+}
+
+impl HirDisplay for Module {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        // FIXME: Module doesn't have visibility saved in data.
+        match self.name(f.db) {
+            Some(name) => write!(f, "mod {}", name),
+            None if self.crate_root(f.db) == *self => match self.krate().display_name(f.db) {
+                Some(name) => write!(f, "extern crate {}", name),
+                None => write!(f, "extern crate {{unknown}}"),
+            },
+            None => write!(f, "mod {{unnamed}}"),
+        }
+    }
+}
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 079a5f7b8..ad79a79f8 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -29,6 +29,8 @@ mod has_source;
 pub mod diagnostics;
 pub mod db;
 
+mod display;
+
 use std::{iter, sync::Arc};
 
 use arrayvec::ArrayVec;
@@ -50,8 +52,8 @@ use hir_def::{
 use hir_expand::{diagnostics::DiagnosticSink, name::name, MacroDefKind};
 use hir_ty::{
     autoderef,
-    display::{write_bounds_like_dyn_trait_with_prefix, HirDisplayError, HirFormatter},
     method_resolution::{self, TyFingerprint},
+    primitive::UintTy,
     to_assoc_type_id,
     traits::{FnTrait, Solution, SolutionVariables},
     AliasTy, BoundVar, CallableDefId, CallableSig, Canonical, DebruijnIndex, GenericPredicate,
@@ -579,6 +581,12 @@ impl Struct {
     }
 }
 
+impl HasVisibility for Struct {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
+        db.struct_data(self.id).visibility.resolve(db.upcast(), &self.id.resolver(db.upcast()))
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Union {
     pub(crate) id: UnionId,
@@ -611,6 +619,12 @@ impl Union {
     }
 }
 
+impl HasVisibility for Union {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
+        db.union_data(self.id).visibility.resolve(db.upcast(), &self.id.resolver(db.upcast()))
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Enum {
     pub(crate) id: EnumId,
@@ -638,6 +652,12 @@ impl Enum {
     }
 }
 
+impl HasVisibility for Enum {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
+        db.enum_data(self.id).visibility.resolve(db.upcast(), &self.id.resolver(db.upcast()))
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Variant {
     pub(crate) parent: Enum,
@@ -829,7 +849,8 @@ impl Function {
         db.function_data(self.id)
             .params
             .iter()
-            .map(|type_ref| {
+            .enumerate()
+            .map(|(idx, type_ref)| {
                 let ty = Type {
                     krate,
                     ty: InEnvironment {
@@ -837,7 +858,7 @@ impl Function {
                         environment: environment.clone(),
                     },
                 };
-                Param { ty }
+                Param { func: self, ty, idx }
             })
             .collect()
     }
@@ -851,7 +872,7 @@ impl Function {
     }
 
     pub fn is_unsafe(self, db: &dyn HirDatabase) -> bool {
-        db.function_data(self.id).is_unsafe
+        db.function_data(self.id).qualifier.is_unsafe
     }
 
     pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
@@ -900,6 +921,9 @@ impl From<hir_ty::Mutability> for Access {
 
 #[derive(Debug)]
 pub struct Param {
+    func: Function,
+    /// The index in parameter list, including self parameter.
+    idx: usize,
     ty: Type,
 }
 
@@ -907,6 +931,15 @@ impl Param {
     pub fn ty(&self) -> &Type {
         &self.ty
     }
+
+    pub fn pattern_source(&self, db: &dyn HirDatabase) -> Option<ast::Pat> {
+        let params = self.func.source(db)?.value.param_list()?;
+        if params.self_param().is_some() {
+            params.params().nth(self.idx.checked_sub(1)?)?.pat()
+        } else {
+            params.params().nth(self.idx)?.pat()
+        }
+    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -929,6 +962,14 @@ impl SelfParam {
             })
             .unwrap_or(Access::Owned)
     }
+
+    pub fn display(self, db: &dyn HirDatabase) -> &'static str {
+        match self.access(db) {
+            Access::Shared => "&self",
+            Access::Exclusive => "&mut self",
+            Access::Owned => "self",
+        }
+    }
 }
 
 impl HasVisibility for Function {
@@ -956,6 +997,10 @@ impl Const {
     pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
         db.const_data(self.id).name.clone()
     }
+
+    pub fn type_ref(self, db: &dyn HirDatabase) -> TypeRef {
+        db.const_data(self.id).type_ref.clone()
+    }
 }
 
 impl HasVisibility for Const {
@@ -989,6 +1034,12 @@ impl Static {
     }
 }
 
+impl HasVisibility for Static {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
+        db.static_data(self.id).visibility.resolve(db.upcast(), &self.id.resolver(db.upcast()))
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Trait {
     pub(crate) id: TraitId,
@@ -1008,7 +1059,13 @@ impl Trait {
     }
 
     pub fn is_auto(self, db: &dyn HirDatabase) -> bool {
-        db.trait_data(self.id).auto
+        db.trait_data(self.id).is_auto
+    }
+}
+
+impl HasVisibility for Trait {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
+        db.trait_data(self.id).visibility.resolve(db.upcast(), &self.id.resolver(db.upcast()))
     }
 }
 
@@ -1420,19 +1477,6 @@ impl TypeParam {
     }
 }
 
-impl HirDisplay for TypeParam {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
-        write!(f, "{}", self.name(f.db))?;
-        let bounds = f.db.generic_predicates_for_param(self.id);
-        let substs = Substs::type_params(f.db, self.id.parent);
-        let predicates = bounds.iter().cloned().map(|b| b.subst(&substs)).collect::<Vec<_>>();
-        if !(predicates.is_empty() || f.omit_verbose_types()) {
-            write_bounds_like_dyn_trait_with_prefix(":", &predicates, f)?;
-        }
-        Ok(())
-    }
-}
-
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct LifetimeParam {
     pub(crate) id: LifetimeParamId,
@@ -1646,6 +1690,10 @@ impl Type {
         matches!(self.ty.value.interned(&Interner), TyKind::Ref(hir_ty::Mutability::Mut, ..))
     }
 
+    pub fn is_usize(&self) -> bool {
+        matches!(self.ty.value.interned(&Interner), TyKind::Scalar(Scalar::Uint(UintTy::Usize)))
+    }
+
     pub fn remove_ref(&self) -> Option<Type> {
         match &self.ty.value.interned(&Interner) {
             TyKind::Ref(.., ty) => Some(self.derived(ty.clone())),
@@ -2069,12 +2117,6 @@ impl Type {
     }
 }
 
-impl HirDisplay for Type {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
-        self.ty.value.hir_fmt(f)
-    }
-}
-
 // FIXME: closures
 #[derive(Debug)]
 pub struct Callable {
diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index 945638cc5..03c9371b5 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -143,6 +143,12 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.imp.diagnostics_display_range(diagnostics)
     }
 
+    pub fn token_ancestors_with_macros(
+        &self,
+        token: SyntaxToken,
+    ) -> impl Iterator<Item = SyntaxNode> + '_ {
+        token.parent().into_iter().flat_map(move |it| self.ancestors_with_macros(it))
+    }
     pub fn ancestors_with_macros(&self, node: SyntaxNode) -> impl Iterator<Item = SyntaxNode> + '_ {
         self.imp.ancestors_with_macros(node)
     }
@@ -259,6 +265,10 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
     }
 
     pub fn to_module_def(&self, file: FileId) -> Option<Module> {
+        self.imp.to_module_def(file).next()
+    }
+
+    pub fn to_module_defs(&self, file: FileId) -> impl Iterator<Item = Module> {
         self.imp.to_module_def(file)
     }
 
@@ -266,8 +276,8 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.imp.scope(node)
     }
 
-    pub fn scope_at_offset(&self, node: &SyntaxNode, offset: TextSize) -> SemanticsScope<'db> {
-        self.imp.scope_at_offset(node, offset)
+    pub fn scope_at_offset(&self, token: &SyntaxToken, offset: TextSize) -> SemanticsScope<'db> {
+        self.imp.scope_at_offset(&token.parent().unwrap(), offset)
     }
 
     pub fn scope_for_def(&self, def: Trait) -> SemanticsScope<'db> {
@@ -337,7 +347,10 @@ impl<'db> SemanticsImpl<'db> {
 
     fn descend_into_macros(&self, token: SyntaxToken) -> SyntaxToken {
         let _p = profile::span("descend_into_macros");
-        let parent = token.parent();
+        let parent = match token.parent() {
+            Some(it) => it,
+            None => return token,
+        };
         let sa = self.analyze(&parent);
 
         let token = successors(Some(InFile::new(sa.file_id, token)), |token| {
@@ -356,7 +369,9 @@ impl<'db> SemanticsImpl<'db> {
                 .as_ref()?
                 .map_token_down(token.as_ref())?;
 
-            self.cache(find_root(&token.value.parent()), token.file_id);
+            if let Some(parent) = token.value.parent() {
+                self.cache(find_root(&parent), token.file_id);
+            }
 
             Some(token)
         })
@@ -374,7 +389,7 @@ impl<'db> SemanticsImpl<'db> {
         // Handle macro token cases
         node.token_at_offset(offset)
             .map(|token| self.descend_into_macros(token))
-            .map(|it| self.ancestors_with_macros(it.parent()))
+            .map(|it| self.token_ancestors_with_macros(it))
             .flatten()
     }
 
@@ -390,6 +405,13 @@ impl<'db> SemanticsImpl<'db> {
         src.with_value(&node).original_file_range(self.db.upcast())
     }
 
+    fn token_ancestors_with_macros(
+        &self,
+        token: SyntaxToken,
+    ) -> impl Iterator<Item = SyntaxNode> + '_ {
+        token.parent().into_iter().flat_map(move |parent| self.ancestors_with_macros(parent))
+    }
+
     fn ancestors_with_macros(&self, node: SyntaxNode) -> impl Iterator<Item = SyntaxNode> + '_ {
         let node = self.find_file(node);
         node.ancestors_with_macros(self.db.upcast()).map(|it| it.value)
@@ -401,7 +423,7 @@ impl<'db> SemanticsImpl<'db> {
         offset: TextSize,
     ) -> impl Iterator<Item = SyntaxNode> + '_ {
         node.token_at_offset(offset)
-            .map(|token| self.ancestors_with_macros(token.parent()))
+            .map(|token| self.token_ancestors_with_macros(token))
             .kmerge_by(|node1, node2| node1.text_range().len() < node2.text_range().len())
     }
 
@@ -537,8 +559,8 @@ impl<'db> SemanticsImpl<'db> {
         f(&mut ctx)
     }
 
-    fn to_module_def(&self, file: FileId) -> Option<Module> {
-        self.with_ctx(|ctx| ctx.file_to_def(file)).map(Module::from)
+    fn to_module_def(&self, file: FileId) -> impl Iterator<Item = Module> {
+        self.with_ctx(|ctx| ctx.file_to_def(file)).into_iter().map(Module::from)
     }
 
     fn scope(&self, node: &SyntaxNode) -> SemanticsScope<'db> {
diff --git a/crates/hir/src/semantics/source_to_def.rs b/crates/hir/src/semantics/source_to_def.rs
index 6c612ee86..e9d820140 100644
--- a/crates/hir/src/semantics/source_to_def.rs
+++ b/crates/hir/src/semantics/source_to_def.rs
@@ -12,6 +12,7 @@ use hir_def::{
 };
 use hir_expand::{name::AsName, AstId, MacroDefKind};
 use rustc_hash::FxHashMap;
+use smallvec::SmallVec;
 use stdx::impl_from;
 use syntax::{
     ast::{self, NameOwner},
@@ -28,14 +29,19 @@ pub(super) struct SourceToDefCtx<'a, 'b> {
 }
 
 impl SourceToDefCtx<'_, '_> {
-    pub(super) fn file_to_def(&mut self, file: FileId) -> Option<ModuleId> {
+    pub(super) fn file_to_def(&mut self, file: FileId) -> SmallVec<[ModuleId; 1]> {
         let _p = profile::span("SourceBinder::to_module_def");
-        self.db.relevant_crates(file).iter().find_map(|&crate_id| {
+        let mut mods = SmallVec::new();
+        for &crate_id in self.db.relevant_crates(file).iter() {
             // FIXME: inner items
             let crate_def_map = self.db.crate_def_map(crate_id);
-            let local_id = crate_def_map.modules_for_file(file).next()?;
-            Some(crate_def_map.module_id(local_id))
-        })
+            mods.extend(
+                crate_def_map
+                    .modules_for_file(file)
+                    .map(|local_id| crate_def_map.module_id(local_id)),
+            )
+        }
+        mods
     }
 
     pub(super) fn module_to_def(&mut self, src: InFile<ast::Module>) -> Option<ModuleId> {
@@ -55,7 +61,7 @@ impl SourceToDefCtx<'_, '_> {
             Some(parent_declaration) => self.module_to_def(parent_declaration),
             None => {
                 let file_id = src.file_id.original_file(self.db.upcast());
-                self.file_to_def(file_id)
+                self.file_to_def(file_id).get(0).copied()
             }
         }?;
 
@@ -185,7 +191,7 @@ impl SourceToDefCtx<'_, '_> {
     ) -> Option<MacroDefId> {
         let kind = MacroDefKind::Declarative;
         let file_id = src.file_id.original_file(self.db.upcast());
-        let krate = self.file_to_def(file_id)?.krate();
+        let krate = self.file_to_def(file_id).get(0).copied()?.krate();
         let file_ast_id = self.db.ast_id_map(src.file_id).ast_id(&src.value);
         let ast_id = Some(AstId::new(src.file_id, file_ast_id.upcast()));
         Some(MacroDefId { krate, ast_id, kind, local_inner: false })
@@ -245,7 +251,7 @@ impl SourceToDefCtx<'_, '_> {
             return Some(res);
         }
 
-        let def = self.file_to_def(src.file_id.original_file(self.db.upcast()))?;
+        let def = self.file_to_def(src.file_id.original_file(self.db.upcast())).get(0).copied()?;
         Some(def.into())
     }
 
diff --git a/crates/hir_def/src/adt.rs b/crates/hir_def/src/adt.rs
index efbde17d8..1b9bb8235 100644
--- a/crates/hir_def/src/adt.rs
+++ b/crates/hir_def/src/adt.rs
@@ -31,12 +31,14 @@ pub struct StructData {
     pub name: Name,
     pub variant_data: Arc<VariantData>,
     pub repr: Option<ReprKind>,
+    pub visibility: RawVisibility,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct EnumData {
     pub name: Name,
     pub variants: Arena<EnumVariantData>,
+    pub visibility: RawVisibility,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -102,6 +104,7 @@ impl StructData {
             name: strukt.name.clone(),
             variant_data: Arc::new(variant_data),
             repr,
+            visibility: item_tree[strukt.visibility].clone(),
         })
     }
     pub(crate) fn union_data_query(db: &dyn DefDatabase, id: UnionId) -> Arc<StructData> {
@@ -118,6 +121,7 @@ impl StructData {
             name: union.name.clone(),
             variant_data: Arc::new(variant_data),
             repr,
+            visibility: item_tree[union.visibility].clone(),
         })
     }
 }
@@ -150,7 +154,11 @@ impl EnumData {
             }
         }
 
-        Arc::new(EnumData { name: enum_.name.clone(), variants })
+        Arc::new(EnumData {
+            name: enum_.name.clone(),
+            variants,
+            visibility: item_tree[enum_.visibility].clone(),
+        })
     }
 
     pub fn variant(&self, name: &Name) -> Option<LocalEnumVariantId> {
diff --git a/crates/hir_def/src/body/lower.rs b/crates/hir_def/src/body/lower.rs
index 8934ae6c9..7052058f2 100644
--- a/crates/hir_def/src/body/lower.rs
+++ b/crates/hir_def/src/body/lower.rs
@@ -519,7 +519,7 @@ impl ExprCollector<'_> {
             }
             ast::Expr::MacroCall(e) => {
                 let mut ids = vec![];
-                self.collect_macro_call(e, syntax_ptr.clone(), |this, expansion| {
+                self.collect_macro_call(e, syntax_ptr.clone(), true, |this, expansion| {
                     ids.push(match expansion {
                         Some(it) => this.collect_expr(it),
                         None => this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
@@ -527,6 +527,17 @@ impl ExprCollector<'_> {
                 });
                 ids[0]
             }
+            ast::Expr::MacroStmts(e) => {
+                // FIXME:  these statements should be held by some hir containter
+                for stmt in e.statements() {
+                    self.collect_stmt(stmt);
+                }
+                if let Some(expr) = e.expr() {
+                    self.collect_expr(expr)
+                } else {
+                    self.alloc_expr(Expr::Missing, syntax_ptr)
+                }
+            }
         }
     }
 
@@ -534,6 +545,7 @@ impl ExprCollector<'_> {
         &mut self,
         e: ast::MacroCall,
         syntax_ptr: AstPtr<ast::Expr>,
+        is_error_recoverable: bool,
         mut collector: F,
     ) {
         // File containing the macro call. Expansion errors will be attached here.
@@ -567,7 +579,7 @@ impl ExprCollector<'_> {
             Some((mark, expansion)) => {
                 // FIXME: Statements are too complicated to recover from error for now.
                 // It is because we don't have any hygiene for local variable expansion right now.
-                if T::can_cast(syntax::SyntaxKind::MACRO_STMTS) && res.err.is_some() {
+                if !is_error_recoverable && res.err.is_some() {
                     self.expander.exit(self.db, mark);
                     collector(self, None);
                 } else {
@@ -591,56 +603,55 @@ impl ExprCollector<'_> {
     }
 
     fn collect_stmt(&mut self, s: ast::Stmt) -> Option<Vec<Statement>> {
-        let stmt =
-            match s {
-                ast::Stmt::LetStmt(stmt) => {
-                    self.check_cfg(&stmt)?;
-
-                    let pat = self.collect_pat_opt(stmt.pat());
-                    let type_ref = stmt.ty().map(|it| TypeRef::from_ast(&self.ctx(), it));
-                    let initializer = stmt.initializer().map(|e| self.collect_expr(e));
-                    vec![Statement::Let { pat, type_ref, initializer }]
-                }
-                ast::Stmt::ExprStmt(stmt) => {
-                    self.check_cfg(&stmt)?;
-
-                    // Note that macro could be expended to multiple statements
-                    if let Some(ast::Expr::MacroCall(m)) = stmt.expr() {
-                        let syntax_ptr = AstPtr::new(&stmt.expr().unwrap());
-                        let mut stmts = vec![];
-
-                        self.collect_macro_call(m, syntax_ptr.clone(), |this, expansion| {
-                            match expansion {
-                                Some(expansion) => {
-                                    let statements: ast::MacroStmts = expansion;
-
-                                    statements.statements().for_each(|stmt| {
-                                        if let Some(mut r) = this.collect_stmt(stmt) {
-                                            stmts.append(&mut r);
-                                        }
-                                    });
-                                    if let Some(expr) = statements.expr() {
-                                        stmts.push(Statement::Expr(this.collect_expr(expr)));
+        let stmt = match s {
+            ast::Stmt::LetStmt(stmt) => {
+                self.check_cfg(&stmt)?;
+
+                let pat = self.collect_pat_opt(stmt.pat());
+                let type_ref = stmt.ty().map(|it| TypeRef::from_ast(&self.ctx(), it));
+                let initializer = stmt.initializer().map(|e| self.collect_expr(e));
+                vec![Statement::Let { pat, type_ref, initializer }]
+            }
+            ast::Stmt::ExprStmt(stmt) => {
+                self.check_cfg(&stmt)?;
+
+                // Note that macro could be expended to multiple statements
+                if let Some(ast::Expr::MacroCall(m)) = stmt.expr() {
+                    let syntax_ptr = AstPtr::new(&stmt.expr().unwrap());
+                    let mut stmts = vec![];
+
+                    self.collect_macro_call(m, syntax_ptr.clone(), false, |this, expansion| {
+                        match expansion {
+                            Some(expansion) => {
+                                let statements: ast::MacroStmts = expansion;
+
+                                statements.statements().for_each(|stmt| {
+                                    if let Some(mut r) = this.collect_stmt(stmt) {
+                                        stmts.append(&mut r);
                                     }
-                                }
-                                None => {
-                                    stmts.push(Statement::Expr(
-                                        this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
-                                    ));
+                                });
+                                if let Some(expr) = statements.expr() {
+                                    stmts.push(Statement::Expr(this.collect_expr(expr)));
                                 }
                             }
-                        });
-                        stmts
-                    } else {
-                        vec![Statement::Expr(self.collect_expr_opt(stmt.expr()))]
-                    }
+                            None => {
+                                stmts.push(Statement::Expr(
+                                    this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
+                                ));
+                            }
+                        }
+                    });
+                    stmts
+                } else {
+                    vec![Statement::Expr(self.collect_expr_opt(stmt.expr()))]
                 }
-                ast::Stmt::Item(item) => {
-                    self.check_cfg(&item)?;
+            }
+            ast::Stmt::Item(item) => {
+                self.check_cfg(&item)?;
 
-                    return None;
-                }
-            };
+                return None;
+            }
+        };
 
         Some(stmt)
     }
diff --git a/crates/hir_def/src/data.rs b/crates/hir_def/src/data.rs
index aea53d527..74a2194e5 100644
--- a/crates/hir_def/src/data.rs
+++ b/crates/hir_def/src/data.rs
@@ -9,7 +9,7 @@ use crate::{
     attr::Attrs,
     body::Expander,
     db::DefDatabase,
-    item_tree::{AssocItem, ItemTreeId, ModItem},
+    item_tree::{AssocItem, FunctionQualifier, ItemTreeId, ModItem},
     type_ref::{TypeBound, TypeRef},
     visibility::RawVisibility,
     AssocContainerId, AssocItemId, ConstId, ConstLoc, FunctionId, FunctionLoc, HasModule, ImplId,
@@ -26,9 +26,9 @@ pub struct FunctionData {
     /// can be called as a method.
     pub has_self_param: bool,
     pub has_body: bool,
-    pub is_unsafe: bool,
+    pub qualifier: FunctionQualifier,
+    pub is_in_extern_block: bool,
     pub is_varargs: bool,
-    pub is_extern: bool,
     pub visibility: RawVisibility,
 }
 
@@ -46,9 +46,9 @@ impl FunctionData {
             attrs: item_tree.attrs(db, krate, ModItem::from(loc.id.value).into()),
             has_self_param: func.has_self_param,
             has_body: func.has_body,
-            is_unsafe: func.is_unsafe,
+            qualifier: func.qualifier.clone(),
+            is_in_extern_block: func.is_in_extern_block,
             is_varargs: func.is_varargs,
-            is_extern: func.is_extern,
             visibility: item_tree[func.visibility].clone(),
         })
     }
@@ -87,7 +87,10 @@ impl TypeAliasData {
 pub struct TraitData {
     pub name: Name,
     pub items: Vec<(Name, AssocItemId)>,
-    pub auto: bool,
+    pub is_auto: bool,
+    pub is_unsafe: bool,
+    pub visibility: RawVisibility,
+    pub bounds: Box<[TypeBound]>,
 }
 
 impl TraitData {
@@ -96,10 +99,13 @@ impl TraitData {
         let item_tree = db.item_tree(tr_loc.id.file_id);
         let tr_def = &item_tree[tr_loc.id.value];
         let name = tr_def.name.clone();
-        let auto = tr_def.auto;
+        let is_auto = tr_def.is_auto;
+        let is_unsafe = tr_def.is_unsafe;
         let module_id = tr_loc.container;
         let container = AssocContainerId::TraitId(tr);
         let mut expander = Expander::new(db, tr_loc.id.file_id, module_id);
+        let visibility = item_tree[tr_def.visibility].clone();
+        let bounds = tr_def.bounds.clone();
 
         let items = collect_items(
             db,
@@ -111,7 +117,7 @@ impl TraitData {
             100,
         );
 
-        Arc::new(TraitData { name, items, auto })
+        Arc::new(TraitData { name, items, is_auto, is_unsafe, visibility, bounds })
     }
 
     pub fn associated_types(&self) -> impl Iterator<Item = TypeAliasId> + '_ {
diff --git a/crates/hir_def/src/diagnostics.rs b/crates/hir_def/src/diagnostics.rs
index ac7474f63..7188bb299 100644
--- a/crates/hir_def/src/diagnostics.rs
+++ b/crates/hir_def/src/diagnostics.rs
@@ -97,7 +97,7 @@ impl Diagnostic for UnresolvedImport {
 
 // Diagnostic: unresolved-macro-call
 //
-// This diagnostic is triggered if rust-analyzer is unable to resolove path to a
+// This diagnostic is triggered if rust-analyzer is unable to resolve the path to a
 // macro in a macro invocation.
 #[derive(Debug)]
 pub struct UnresolvedMacroCall {
diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index 09bcb10dc..7bb22c4c4 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -24,7 +24,7 @@ use la_arena::{Arena, Idx, RawIdx};
 use profile::Count;
 use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
-use syntax::{ast, match_ast, SyntaxKind};
+use syntax::{ast, match_ast, SmolStr, SyntaxKind};
 
 use crate::{
     attr::{Attrs, RawAttrs},
@@ -110,6 +110,11 @@ impl ItemTree {
                     // still need to collect inner items.
                     ctx.lower_inner_items(e.syntax())
                 },
+                ast::ExprStmt(stmt) => {
+                    // Macros can expand to stmt. We return an empty item tree in this case, but
+                    // still need to collect inner items.
+                    ctx.lower_inner_items(stmt.syntax())
+                },
                 _ => {
                     panic!("cannot create item tree from {:?} {}", syntax, syntax);
                 },
@@ -551,16 +556,25 @@ pub struct Function {
     pub generic_params: GenericParamsId,
     pub has_self_param: bool,
     pub has_body: bool,
-    pub is_unsafe: bool,
+    pub qualifier: FunctionQualifier,
     /// Whether the function is located in an `extern` block (*not* whether it is an
     /// `extern "abi" fn`).
-    pub is_extern: bool,
+    pub is_in_extern_block: bool,
     pub params: Box<[Idx<TypeRef>]>,
     pub is_varargs: bool,
     pub ret_type: Idx<TypeRef>,
     pub ast_id: FileAstId<ast::Fn>,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct FunctionQualifier {
+    pub is_default: bool,
+    pub is_const: bool,
+    pub is_async: bool,
+    pub is_unsafe: bool,
+    pub abi: Option<SmolStr>,
+}
+
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct Struct {
     pub name: Name,
@@ -624,7 +638,9 @@ pub struct Trait {
     pub name: Name,
     pub visibility: RawVisibilityId,
     pub generic_params: GenericParamsId,
-    pub auto: bool,
+    pub is_auto: bool,
+    pub is_unsafe: bool,
+    pub bounds: Box<[TypeBound]>,
     pub items: Box<[AssocItem]>,
     pub ast_id: FileAstId<ast::Trait>,
 }
diff --git a/crates/hir_def/src/item_tree/lower.rs b/crates/hir_def/src/item_tree/lower.rs
index 240fdacf9..7e91b991d 100644
--- a/crates/hir_def/src/item_tree/lower.rs
+++ b/crates/hir_def/src/item_tree/lower.rs
@@ -391,14 +391,33 @@ impl Ctx {
         let has_body = func.body().is_some();
 
         let ast_id = self.source_ast_id_map.ast_id(func);
+        let qualifier = FunctionQualifier {
+            is_default: func.default_token().is_some(),
+            is_const: func.const_token().is_some(),
+            is_async: func.async_token().is_some(),
+            is_unsafe: func.unsafe_token().is_some(),
+            abi: func.abi().map(|abi| {
+                // FIXME: Abi::abi() -> Option<SyntaxToken>?
+                match abi.syntax().last_token() {
+                    Some(tok) if tok.kind() == SyntaxKind::STRING => {
+                        // FIXME: Better way to unescape?
+                        tok.text().trim_matches('"').into()
+                    }
+                    _ => {
+                        // `extern` default to be `extern "C"`.
+                        "C".into()
+                    }
+                }
+            }),
+        };
         let mut res = Function {
             name,
             visibility,
             generic_params: GenericParamsId::EMPTY,
             has_self_param,
             has_body,
-            is_unsafe: func.unsafe_token().is_some(),
-            is_extern: false,
+            qualifier,
+            is_in_extern_block: false,
             params,
             is_varargs,
             ret_type,
@@ -481,7 +500,9 @@ impl Ctx {
         let visibility = self.lower_visibility(trait_def);
         let generic_params =
             self.lower_generic_params_and_inner_items(GenericsOwner::Trait(trait_def), trait_def);
-        let auto = trait_def.auto_token().is_some();
+        let is_auto = trait_def.auto_token().is_some();
+        let is_unsafe = trait_def.unsafe_token().is_some();
+        let bounds = self.lower_type_bounds(trait_def);
         let items = trait_def.assoc_item_list().map(|list| {
             self.with_inherited_visibility(visibility, |this| {
                 list.assoc_items()
@@ -501,7 +522,9 @@ impl Ctx {
             name,
             visibility,
             generic_params,
-            auto,
+            is_auto,
+            is_unsafe,
+            bounds: bounds.into(),
             items: items.unwrap_or_default(),
             ast_id,
         };
@@ -608,8 +631,8 @@ impl Ctx {
                         ast::ExternItem::Fn(ast) => {
                             let func_id = self.lower_function(&ast)?;
                             let func = &mut self.data().functions[func_id.index];
-                            func.is_unsafe = is_intrinsic_fn_unsafe(&func.name);
-                            func.is_extern = true;
+                            func.qualifier.is_unsafe = is_intrinsic_fn_unsafe(&func.name);
+                            func.is_in_extern_block = true;
                             func_id.into()
                         }
                         ast::ExternItem::Static(ast) => {
diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index 9ed48c506..81cf652b0 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -13,7 +13,7 @@ use hir_expand::{
     builtin_macro::find_builtin_macro,
     name::{AsName, Name},
     proc_macro::ProcMacroExpander,
-    HirFileId, MacroCallId, MacroDefId, MacroDefKind,
+    HirFileId, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
 };
 use hir_expand::{InFile, MacroCallLoc};
 use rustc_hash::{FxHashMap, FxHashSet};
@@ -1455,7 +1455,8 @@ impl ModCollector<'_, '_> {
         let mut ast_id = AstIdWithPath::new(self.file_id, mac.ast_id, mac.path.clone());
 
         // Case 1: try to resolve in legacy scope and expand macro_rules
-        if let Ok(Ok(macro_call_id)) = macro_call_as_call_id(
+        let mut error = None;
+        match macro_call_as_call_id(
             &ast_id,
             self.def_collector.db,
             self.def_collector.def_map.krate,
@@ -1468,16 +1469,28 @@ impl ModCollector<'_, '_> {
                     )
                 })
             },
-            &mut |_err| (),
+            &mut |err| error = Some(err),
         ) {
-            self.def_collector.unexpanded_macros.push(MacroDirective {
-                module_id: self.module_id,
-                ast_id,
-                legacy: Some(macro_call_id),
-                depth: self.macro_depth + 1,
-            });
+            Ok(Ok(macro_call_id)) => {
+                self.def_collector.unexpanded_macros.push(MacroDirective {
+                    module_id: self.module_id,
+                    ast_id,
+                    legacy: Some(macro_call_id),
+                    depth: self.macro_depth + 1,
+                });
 
-            return;
+                return;
+            }
+            Ok(Err(_)) => {
+                // Built-in macro failed eager expansion.
+                self.def_collector.def_map.diagnostics.push(DefDiagnostic::macro_error(
+                    self.module_id,
+                    MacroCallKind::FnLike(ast_id.ast_id),
+                    error.unwrap().to_string(),
+                ));
+                return;
+            }
+            Err(UnresolvedMacro) => (),
         }
 
         // Case 2: resolve in module scope, expand during name resolution.
diff --git a/crates/hir_def/src/nameres/tests/diagnostics.rs b/crates/hir_def/src/nameres/tests/diagnostics.rs
index 1b8e885b0..c22ef46fd 100644
--- a/crates/hir_def/src/nameres/tests/diagnostics.rs
+++ b/crates/hir_def/src/nameres/tests/diagnostics.rs
@@ -155,3 +155,48 @@ fn inactive_via_cfg_attr() {
         "#,
     );
 }
+
+#[test]
+fn unresolved_legacy_scope_macro() {
+    check_diagnostics(
+        r#"
+        //- /lib.rs
+          macro_rules! m { () => {} }
+
+          m!();
+          m2!();
+        //^^^^^^ unresolved macro call
+        "#,
+    );
+}
+
+#[test]
+fn unresolved_module_scope_macro() {
+    check_diagnostics(
+        r#"
+        //- /lib.rs
+          mod mac {
+            #[macro_export]
+            macro_rules! m { () => {} }
+          }
+
+          self::m!();
+          self::m2!();
+        //^^^^^^^^^^^^ unresolved macro call
+        "#,
+    );
+}
+
+#[test]
+fn builtin_macro_fails_expansion() {
+    check_diagnostics(
+        r#"
+        //- /lib.rs
+          #[rustc_builtin_macro]
+          macro_rules! include { () => {} }
+
+          include!("doesntexist");
+        //^^^^^^^^^^^^^^^^^^^^^^^^ could not convert tokens
+        "#,
+    );
+}
diff --git a/crates/hir_def/src/path.rs b/crates/hir_def/src/path.rs
index 0e60dc2b6..8c923bb7b 100644
--- a/crates/hir_def/src/path.rs
+++ b/crates/hir_def/src/path.rs
@@ -9,7 +9,10 @@ use std::{
 
 use crate::{body::LowerCtx, type_ref::LifetimeRef};
 use base_db::CrateId;
-use hir_expand::{hygiene::Hygiene, name::Name};
+use hir_expand::{
+    hygiene::Hygiene,
+    name::{name, Name},
+};
 use syntax::ast;
 
 use crate::{
@@ -209,6 +212,12 @@ impl Path {
         };
         Some(res)
     }
+
+    pub fn is_self_type(&self) -> bool {
+        self.type_anchor.is_none()
+            && self.generic_args == &[None]
+            && self.mod_path.as_ident() == Some(&name!(Self))
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
diff --git a/crates/hir_expand/src/db.rs b/crates/hir_expand/src/db.rs
index 9086e6c17..a3070f1f9 100644
--- a/crates/hir_expand/src/db.rs
+++ b/crates/hir_expand/src/db.rs
@@ -401,13 +401,14 @@ fn to_fragment_kind(db: &dyn AstDatabase, id: MacroCallId) -> FragmentKind {
 
     match parent.kind() {
         MACRO_ITEMS | SOURCE_FILE => FragmentKind::Items,
+        MACRO_STMTS => FragmentKind::Statement,
         ITEM_LIST => FragmentKind::Items,
         LET_STMT => {
             // FIXME: Handle Pattern
             FragmentKind::Expr
         }
         EXPR_STMT => FragmentKind::Statements,
-        BLOCK_EXPR => FragmentKind::Expr,
+        BLOCK_EXPR => FragmentKind::Statements,
         ARG_LIST => FragmentKind::Expr,
         TRY_EXPR => FragmentKind::Expr,
         TUPLE_EXPR => FragmentKind::Expr,
diff --git a/crates/hir_expand/src/lib.rs b/crates/hir_expand/src/lib.rs
index e388ddacc..eee430af1 100644
--- a/crates/hir_expand/src/lib.rs
+++ b/crates/hir_expand/src/lib.rs
@@ -510,7 +510,10 @@ impl InFile<SyntaxToken> {
         self,
         db: &dyn db::AstDatabase,
     ) -> impl Iterator<Item = InFile<SyntaxNode>> + '_ {
-        self.map(|it| it.parent()).ancestors_with_macros(db)
+        self.value
+            .parent()
+            .into_iter()
+            .flat_map(move |parent| InFile::new(self.file_id, parent).ancestors_with_macros(db))
     }
 }
 
diff --git a/crates/hir_expand/src/name.rs b/crates/hir_expand/src/name.rs
index e833e032c..43de9edd6 100644
--- a/crates/hir_expand/src/name.rs
+++ b/crates/hir_expand/src/name.rs
@@ -191,6 +191,8 @@ pub mod known {
         filter_map,
         next,
         iter_mut,
+        len,
+        is_empty,
         // Builtin macros
         file,
         column,
diff --git a/crates/hir_ty/src/diagnostics/decl_check.rs b/crates/hir_ty/src/diagnostics/decl_check.rs
index 3605ca581..982ad5b9e 100644
--- a/crates/hir_ty/src/diagnostics/decl_check.rs
+++ b/crates/hir_ty/src/diagnostics/decl_check.rs
@@ -91,7 +91,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
 
     fn validate_func(&mut self, func: FunctionId) {
         let data = self.db.function_data(func);
-        if data.is_extern {
+        if data.is_in_extern_block {
             cov_mark::hit!(extern_func_incorrect_case_ignored);
             return;
         }
diff --git a/crates/hir_ty/src/diagnostics/unsafe_check.rs b/crates/hir_ty/src/diagnostics/unsafe_check.rs
index 20bb64827..44a7e5506 100644
--- a/crates/hir_ty/src/diagnostics/unsafe_check.rs
+++ b/crates/hir_ty/src/diagnostics/unsafe_check.rs
@@ -32,7 +32,7 @@ impl<'a, 'b> UnsafeValidator<'a, 'b> {
         let def = self.owner.into();
         let unsafe_expressions = unsafe_expressions(db, self.infer.as_ref(), def);
         let is_unsafe = match self.owner {
-            DefWithBodyId::FunctionId(it) => db.function_data(it).is_unsafe,
+            DefWithBodyId::FunctionId(it) => db.function_data(it).qualifier.is_unsafe,
             DefWithBodyId::StaticId(_) | DefWithBodyId::ConstId(_) => false,
         };
         if is_unsafe
@@ -86,7 +86,7 @@ fn walk_unsafe(
     match expr {
         &Expr::Call { callee, .. } => {
             if let Some(func) = infer[callee].as_fn_def(db) {
-                if db.function_data(func).is_unsafe {
+                if db.function_data(func).qualifier.is_unsafe {
                     unsafe_exprs.push(UnsafeExpr { expr: current, inside_unsafe_block });
                 }
             }
@@ -103,7 +103,7 @@ fn walk_unsafe(
         Expr::MethodCall { .. } => {
             if infer
                 .method_resolution(current)
-                .map(|func| db.function_data(func).is_unsafe)
+                .map(|func| db.function_data(func).qualifier.is_unsafe)
                 .unwrap_or(false)
             {
                 unsafe_exprs.push(UnsafeExpr { expr: current, inside_unsafe_block });
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index c1062387e..c572bb114 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -5,7 +5,13 @@ use std::{borrow::Cow, fmt};
 use arrayvec::ArrayVec;
 use chalk_ir::Mutability;
 use hir_def::{
-    db::DefDatabase, find_path, generics::TypeParamProvenance, item_scope::ItemInNs,
+    db::DefDatabase,
+    find_path,
+    generics::TypeParamProvenance,
+    item_scope::ItemInNs,
+    path::{GenericArg, Path, PathKind},
+    type_ref::{TypeBound, TypeRef},
+    visibility::Visibility,
     AssocContainerId, Lookup, ModuleId, TraitId,
 };
 use hir_expand::name::Name;
@@ -232,7 +238,7 @@ where
 
 const TYPE_HINT_TRUNCATION: &str = "…";
 
-impl HirDisplay for &Ty {
+impl<T: HirDisplay> HirDisplay for &'_ T {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         HirDisplay::hir_fmt(*self, f)
     }
@@ -761,12 +767,6 @@ impl HirDisplay for TraitRef {
     }
 }
 
-impl HirDisplay for &GenericPredicate {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
-        HirDisplay::hir_fmt(*self, f)
-    }
-}
-
 impl HirDisplay for GenericPredicate {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
@@ -825,3 +825,190 @@ impl HirDisplay for Obligation {
         }
     }
 }
+
+pub fn write_visibility(
+    module_id: ModuleId,
+    vis: Visibility,
+    f: &mut HirFormatter,
+) -> Result<(), HirDisplayError> {
+    match vis {
+        Visibility::Public => write!(f, "pub "),
+        Visibility::Module(vis_id) => {
+            let def_map = module_id.def_map(f.db.upcast());
+            let root_module_id = def_map.module_id(def_map.root());
+            if vis_id == module_id {
+                // pub(self) or omitted
+                Ok(())
+            } else if root_module_id == vis_id {
+                write!(f, "pub(crate) ")
+            } else if module_id.containing_module(f.db.upcast()) == Some(vis_id) {
+                write!(f, "pub(super) ")
+            } else {
+                write!(f, "pub(in ...) ")
+            }
+        }
+    }
+}
+
+impl HirDisplay for TypeRef {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        match self {
+            TypeRef::Never => write!(f, "!")?,
+            TypeRef::Placeholder => write!(f, "_")?,
+            TypeRef::Tuple(elems) => {
+                write!(f, "(")?;
+                f.write_joined(elems, ", ")?;
+                if elems.len() == 1 {
+                    write!(f, ",")?;
+                }
+                write!(f, ")")?;
+            }
+            TypeRef::Path(path) => path.hir_fmt(f)?,
+            TypeRef::RawPtr(inner, mutability) => {
+                let mutability = match mutability {
+                    hir_def::type_ref::Mutability::Shared => "*const ",
+                    hir_def::type_ref::Mutability::Mut => "*mut ",
+                };
+                write!(f, "{}", mutability)?;
+                inner.hir_fmt(f)?;
+            }
+            TypeRef::Reference(inner, lifetime, mutability) => {
+                let mutability = match mutability {
+                    hir_def::type_ref::Mutability::Shared => "",
+                    hir_def::type_ref::Mutability::Mut => "mut ",
+                };
+                write!(f, "&")?;
+                if let Some(lifetime) = lifetime {
+                    write!(f, "{} ", lifetime.name)?;
+                }
+                write!(f, "{}", mutability)?;
+                inner.hir_fmt(f)?;
+            }
+            TypeRef::Array(inner) => {
+                write!(f, "[")?;
+                inner.hir_fmt(f)?;
+                // FIXME: Array length?
+                write!(f, "; _]")?;
+            }
+            TypeRef::Slice(inner) => {
+                write!(f, "[")?;
+                inner.hir_fmt(f)?;
+                write!(f, "]")?;
+            }
+            TypeRef::Fn(tys, is_varargs) => {
+                // FIXME: Function pointer qualifiers.
+                write!(f, "fn(")?;
+                f.write_joined(&tys[..tys.len() - 1], ", ")?;
+                if *is_varargs {
+                    write!(f, "{}...", if tys.len() == 1 { "" } else { ", " })?;
+                }
+                write!(f, ")")?;
+                let ret_ty = tys.last().unwrap();
+                match ret_ty {
+                    TypeRef::Tuple(tup) if tup.is_empty() => {}
+                    _ => {
+                        write!(f, " -> ")?;
+                        ret_ty.hir_fmt(f)?;
+                    }
+                }
+            }
+            TypeRef::ImplTrait(bounds) => {
+                write!(f, "impl ")?;
+                f.write_joined(bounds, " + ")?;
+            }
+            TypeRef::DynTrait(bounds) => {
+                write!(f, "dyn ")?;
+                f.write_joined(bounds, " + ")?;
+            }
+            TypeRef::Error => write!(f, "{{error}}")?,
+        }
+        Ok(())
+    }
+}
+
+impl HirDisplay for TypeBound {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        match self {
+            TypeBound::Path(path) => path.hir_fmt(f),
+            TypeBound::Lifetime(lifetime) => write!(f, "{}", lifetime.name),
+            TypeBound::Error => write!(f, "{{error}}"),
+        }
+    }
+}
+
+impl HirDisplay for Path {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        match (self.type_anchor(), self.kind()) {
+            (Some(anchor), _) => {
+                write!(f, "<")?;
+                anchor.hir_fmt(f)?;
+                write!(f, ">")?;
+            }
+            (_, PathKind::Plain) => {}
+            (_, PathKind::Abs) => write!(f, "::")?,
+            (_, PathKind::Crate) => write!(f, "crate")?,
+            (_, PathKind::Super(0)) => write!(f, "self")?,
+            (_, PathKind::Super(n)) => {
+                write!(f, "super")?;
+                for _ in 0..*n {
+                    write!(f, "::super")?;
+                }
+            }
+            (_, PathKind::DollarCrate(_)) => write!(f, "{{extern_crate}}")?,
+        }
+
+        for (seg_idx, segment) in self.segments().iter().enumerate() {
+            if seg_idx != 0 {
+                write!(f, "::")?;
+            }
+            write!(f, "{}", segment.name)?;
+            if let Some(generic_args) = segment.args_and_bindings {
+                // We should be in type context, so format as `Foo<Bar>` instead of `Foo::<Bar>`.
+                // Do we actually format expressions?
+                write!(f, "<")?;
+                let mut first = true;
+                for arg in &generic_args.args {
+                    if first {
+                        first = false;
+                        if generic_args.has_self_type {
+                            // FIXME: Convert to `<Ty as Trait>` form.
+                            write!(f, "Self = ")?;
+                        }
+                    } else {
+                        write!(f, ", ")?;
+                    }
+                    arg.hir_fmt(f)?;
+                }
+                for binding in &generic_args.bindings {
+                    if first {
+                        first = false;
+                    } else {
+                        write!(f, ", ")?;
+                    }
+                    write!(f, "{}", binding.name)?;
+                    match &binding.type_ref {
+                        Some(ty) => {
+                            write!(f, " = ")?;
+                            ty.hir_fmt(f)?
+                        }
+                        None => {
+                            write!(f, ": ")?;
+                            f.write_joined(&binding.bounds, " + ")?;
+                        }
+                    }
+                }
+                write!(f, ">")?;
+            }
+        }
+        Ok(())
+    }
+}
+
+impl HirDisplay for GenericArg {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        match self {
+            GenericArg::Type(ty) => ty.hir_fmt(f),
+            GenericArg::Lifetime(lifetime) => write!(f, "{}", lifetime.name),
+        }
+    }
+}
diff --git a/crates/hir_ty/src/infer/unify.rs b/crates/hir_ty/src/infer/unify.rs
index 66f8fe8a3..7795f446f 100644
--- a/crates/hir_ty/src/infer/unify.rs
+++ b/crates/hir_ty/src/infer/unify.rs
@@ -300,7 +300,7 @@ impl InferenceTable {
                 | (TyKind::Raw(_, ty1), TyKind::Raw(_, ty2))
                 | (TyKind::Array(ty1), TyKind::Array(ty2))
                 | (TyKind::Slice(ty1), TyKind::Slice(ty2)) => self.unify_inner(ty1, ty2, depth + 1),
-                _ => false,
+                _ => true, /* we checked equals_ctor already */
             }
         } else {
             self.unify_inner_trivial(&ty1, &ty2, depth)
diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index 503910dde..850385280 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -31,6 +31,7 @@ use hir_def::{
     GenericDefId, HasModule, LifetimeParamId, Lookup, TraitId, TypeAliasId, TypeParamId,
 };
 use itertools::Itertools;
+use smallvec::SmallVec;
 
 use crate::{
     db::HirDatabase,
@@ -272,7 +273,7 @@ impl Ty {
 
 /// A list of substitutions for generic parameters.
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
-pub struct Substs(Arc<[Ty]>);
+pub struct Substs(SmallVec<[Ty; 2]>);
 
 impl TypeWalk for Substs {
     fn walk(&self, f: &mut impl FnMut(&Ty)) {
@@ -286,19 +287,27 @@ impl TypeWalk for Substs {
         f: &mut impl FnMut(&mut Ty, DebruijnIndex),
         binders: DebruijnIndex,
     ) {
-        for t in make_mut_slice(&mut self.0) {
+        for t in &mut self.0 {
             t.walk_mut_binders(f, binders);
         }
     }
 }
 
 impl Substs {
+    pub fn interned(&self, _: &Interner) -> &[Ty] {
+        &self.0
+    }
+
     pub fn empty() -> Substs {
-        Substs(Arc::new([]))
+        Substs(SmallVec::new())
     }
 
     pub fn single(ty: Ty) -> Substs {
-        Substs(Arc::new([ty]))
+        Substs({
+            let mut v = SmallVec::new();
+            v.push(ty);
+            v
+        })
     }
 
     pub fn prefix(&self, n: usize) -> Substs {
@@ -316,6 +325,10 @@ impl Substs {
         &self.0[0]
     }
 
+    pub fn from_iter(_interner: &Interner, elements: impl IntoIterator<Item = Ty>) -> Self {
+        Substs(elements.into_iter().collect())
+    }
+
     /// Return Substs that replace each parameter by itself (i.e. `Ty::Param`).
     pub(crate) fn type_params_for_generics(
         db: &dyn HirDatabase,
@@ -600,13 +613,13 @@ impl CallableSig {
 
     pub fn from_fn_ptr(fn_ptr: &FnPointer) -> CallableSig {
         CallableSig {
-            params_and_return: Arc::clone(&fn_ptr.substs.0),
+            params_and_return: fn_ptr.substs.interned(&Interner).iter().cloned().collect(),
             is_varargs: fn_ptr.sig.variadic,
         }
     }
 
     pub fn from_substs(substs: &Substs) -> CallableSig {
-        CallableSig { params_and_return: Arc::clone(&substs.0), is_varargs: false }
+        CallableSig { params_and_return: substs.iter().cloned().collect(), is_varargs: false }
     }
 
     pub fn params(&self) -> &[Ty] {
@@ -649,7 +662,7 @@ impl Ty {
         TyKind::Function(FnPointer {
             num_args: sig.params().len(),
             sig: FnSig { abi: (), safety: Safety::Safe, variadic: sig.is_varargs },
-            substs: Substs(sig.params_and_return),
+            substs: Substs::from_iter(&Interner, sig.params_and_return.iter().cloned()),
         })
         .intern(&Interner)
     }
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index b4c650fa1..6ab757bfc 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -31,7 +31,7 @@ use crate::{
     traits::chalk::{Interner, ToChalk},
     utils::{
         all_super_trait_refs, associated_type_by_name_including_super_traits, generics,
-        make_mut_slice, variant_data,
+        variant_data,
     },
     AliasTy, Binders, BoundVar, CallableSig, DebruijnIndex, FnPointer, FnSig, GenericPredicate,
     ImplTraitId, OpaqueTy, PolyFnSig, ProjectionPredicate, ProjectionTy, ReturnTypeImplTrait,
@@ -150,8 +150,9 @@ impl<'a> TyLoweringContext<'a> {
         let ty = match type_ref {
             TypeRef::Never => TyKind::Never.intern(&Interner),
             TypeRef::Tuple(inner) => {
-                let inner_tys: Arc<[Ty]> = inner.iter().map(|tr| self.lower_ty(tr)).collect();
-                TyKind::Tuple(inner_tys.len(), Substs(inner_tys)).intern(&Interner)
+                let inner_tys = inner.iter().map(|tr| self.lower_ty(tr));
+                TyKind::Tuple(inner_tys.len(), Substs::from_iter(&Interner, inner_tys))
+                    .intern(&Interner)
             }
             TypeRef::Path(path) => {
                 let (ty, res_) = self.lower_path(path);
@@ -638,7 +639,7 @@ impl<'a> TyLoweringContext<'a> {
     ) -> TraitRef {
         let mut substs = self.trait_ref_substs_from_path(segment, resolved);
         if let Some(self_ty) = explicit_self_ty {
-            make_mut_slice(&mut substs.0)[0] = self_ty;
+            substs.0[0] = self_ty;
         }
         TraitRef { trait_: resolved, substs }
     }
diff --git a/crates/hir_ty/src/tests/macros.rs b/crates/hir_ty/src/tests/macros.rs
index fb3afaedc..af4f8bb11 100644
--- a/crates/hir_ty/src/tests/macros.rs
+++ b/crates/hir_ty/src/tests/macros.rs
@@ -216,6 +216,22 @@ fn expr_macro_expanded_in_various_places() {
 }
 
 #[test]
+fn expr_macro_expanded_in_stmts() {
+    check_infer(
+        r#"
+        macro_rules! id { ($($es:tt)*) => { $($es)* } }
+        fn foo() {
+            id! { let a = (); }
+        }
+        "#,
+        expect![[r#"
+            !0..8 'leta=();': ()
+            57..84 '{     ...); } }': ()
+        "#]],
+    );
+}
+
+#[test]
 fn infer_type_value_macro_having_same_name() {
     check_infer(
         r#"
diff --git a/crates/hir_ty/src/tests/traits.rs b/crates/hir_ty/src/tests/traits.rs
index e185b1c0a..93d3ad020 100644
--- a/crates/hir_ty/src/tests/traits.rs
+++ b/crates/hir_ty/src/tests/traits.rs
@@ -1699,7 +1699,7 @@ fn super_trait_assoc_type_bounds() {
 
 #[test]
 fn fn_trait() {
-    check_infer(
+    check_infer_with_mismatches(
         r#"
         trait FnOnce<Args> {
             type Output;
@@ -1727,7 +1727,7 @@ fn fn_trait() {
 
 #[test]
 fn fn_ptr_and_item() {
-    check_infer(
+    check_infer_with_mismatches(
         r#"
         #[lang="fn_once"]
         trait FnOnce<Args> {
@@ -1743,12 +1743,12 @@ fn fn_ptr_and_item() {
         struct Bar<T>(T);
 
         impl<A1, R, F: FnOnce(A1) -> R> Foo<(A1, R)> for Bar<F> {
-            fn foo(&self) -> (A1, R) {}
+            fn foo(&self) -> (A1, R) { loop {} }
         }
 
         enum Opt<T> { None, Some(T) }
         impl<T> Opt<T> {
-            fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Opt<U> {}
+            fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Opt<U> { loop {} }
         }
 
         fn test() {
@@ -1765,19 +1765,23 @@ fn fn_ptr_and_item() {
             80..84 'args': Args
             139..143 'self': &Self
             243..247 'self': &Bar<F>
-            260..262 '{}': ()
-            346..350 'self': Opt<T>
-            352..353 'f': F
-            368..370 '{}': ()
-            384..500 '{     ...(f); }': ()
-            394..397 'bar': Bar<fn(u8) -> u32>
-            423..426 'bar': Bar<fn(u8) -> u32>
-            423..432 'bar.foo()': (u8, u32)
-            443..446 'opt': Opt<u8>
-            465..466 'f': fn(u8) -> u32
-            487..490 'opt': Opt<u8>
-            487..497 'opt.map(f)': Opt<u32>
-            495..496 'f': fn(u8) -> u32
+            260..271 '{ loop {} }': (A1, R)
+            262..269 'loop {}': !
+            267..269 '{}': ()
+            355..359 'self': Opt<T>
+            361..362 'f': F
+            377..388 '{ loop {} }': Opt<U>
+            379..386 'loop {}': !
+            384..386 '{}': ()
+            402..518 '{     ...(f); }': ()
+            412..415 'bar': Bar<fn(u8) -> u32>
+            441..444 'bar': Bar<fn(u8) -> u32>
+            441..450 'bar.foo()': (u8, u32)
+            461..464 'opt': Opt<u8>
+            483..484 'f': fn(u8) -> u32
+            505..508 'opt': Opt<u8>
+            505..515 'opt.map(f)': Opt<u32>
+            513..514 'f': fn(u8) -> u32
         "#]],
     );
 }
@@ -1859,7 +1863,7 @@ fn fn_trait_deref_with_ty_default() {
 
 #[test]
 fn closure_1() {
-    check_infer(
+    check_infer_with_mismatches(
         r#"
         #[lang = "fn_once"]
         trait FnOnce<Args> {
@@ -1868,7 +1872,7 @@ fn closure_1() {
 
         enum Option<T> { Some(T), None }
         impl<T> Option<T> {
-            fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Option<U> {}
+            fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Option<U> { loop {} }
         }
 
         fn test() {
@@ -1881,37 +1885,39 @@ fn closure_1() {
         expect![[r#"
             147..151 'self': Option<T>
             153..154 'f': F
-            172..174 '{}': ()
-            188..307 '{     ... 1); }': ()
-            198..199 'x': Option<u32>
-            202..214 'Option::Some': Some<u32>(u32) -> Option<u32>
-            202..220 'Option...(1u32)': Option<u32>
-            215..219 '1u32': u32
-            226..227 'x': Option<u32>
-            226..242 'x.map(...v + 1)': Option<u32>
-            232..241 '|v| v + 1': |u32| -> u32
-            233..234 'v': u32
-            236..237 'v': u32
-            236..241 'v + 1': u32
-            240..241 '1': u32
-            248..249 'x': Option<u32>
-            248..264 'x.map(... 1u64)': Option<u64>
-            254..263 '|_v| 1u64': |u32| -> u64
-            255..257 '_v': u32
-            259..263 '1u64': u64
-            274..275 'y': Option<i64>
-            291..292 'x': Option<u32>
-            291..304 'x.map(|_v| 1)': Option<i64>
-            297..303 '|_v| 1': |u32| -> i64
-            298..300 '_v': u32
-            302..303 '1': i64
+            172..183 '{ loop {} }': Option<U>
+            174..181 'loop {}': !
+            179..181 '{}': ()
+            197..316 '{     ... 1); }': ()
+            207..208 'x': Option<u32>
+            211..223 'Option::Some': Some<u32>(u32) -> Option<u32>
+            211..229 'Option...(1u32)': Option<u32>
+            224..228 '1u32': u32
+            235..236 'x': Option<u32>
+            235..251 'x.map(...v + 1)': Option<u32>
+            241..250 '|v| v + 1': |u32| -> u32
+            242..243 'v': u32
+            245..246 'v': u32
+            245..250 'v + 1': u32
+            249..250 '1': u32
+            257..258 'x': Option<u32>
+            257..273 'x.map(... 1u64)': Option<u64>
+            263..272 '|_v| 1u64': |u32| -> u64
+            264..266 '_v': u32
+            268..272 '1u64': u64
+            283..284 'y': Option<i64>
+            300..301 'x': Option<u32>
+            300..313 'x.map(|_v| 1)': Option<i64>
+            306..312 '|_v| 1': |u32| -> i64
+            307..309 '_v': u32
+            311..312 '1': i64
         "#]],
     );
 }
 
 #[test]
 fn closure_2() {
-    check_infer(
+    check_infer_with_mismatches(
         r#"
         trait FnOnce<Args> {
             type Output;
@@ -1951,22 +1957,22 @@ fn closure_2() {
 
 #[test]
 fn closure_as_argument_inference_order() {
-    check_infer(
+    check_infer_with_mismatches(
         r#"
         #[lang = "fn_once"]
         trait FnOnce<Args> {
             type Output;
         }
 
-        fn foo1<T, U, F: FnOnce(T) -> U>(x: T, f: F) -> U {}
-        fn foo2<T, U, F: FnOnce(T) -> U>(f: F, x: T) -> U {}
+        fn foo1<T, U, F: FnOnce(T) -> U>(x: T, f: F) -> U { loop {} }
+        fn foo2<T, U, F: FnOnce(T) -> U>(f: F, x: T) -> U { loop {} }
 
         struct S;
         impl S {
             fn method(self) -> u64;
 
-            fn foo1<T, U, F: FnOnce(T) -> U>(self, x: T, f: F) -> U {}
-            fn foo2<T, U, F: FnOnce(T) -> U>(self, f: F, x: T) -> U {}
+            fn foo1<T, U, F: FnOnce(T) -> U>(self, x: T, f: F) -> U { loop {} }
+            fn foo2<T, U, F: FnOnce(T) -> U>(self, f: F, x: T) -> U { loop {} }
         }
 
         fn test() {
@@ -1979,52 +1985,60 @@ fn closure_as_argument_inference_order() {
         expect![[r#"
             94..95 'x': T
             100..101 'f': F
-            111..113 '{}': ()
-            147..148 'f': F
-            153..154 'x': T
-            164..166 '{}': ()
-            201..205 'self': S
-            253..257 'self': S
-            259..260 'x': T
-            265..266 'f': F
-            276..278 '{}': ()
-            316..320 'self': S
-            322..323 'f': F
-            328..329 'x': T
-            339..341 '{}': ()
-            355..514 '{     ... S); }': ()
-            365..367 'x1': u64
-            370..374 'foo1': fn foo1<S, u64, |S| -> u64>(S, |S| -> u64) -> u64
-            370..393 'foo1(S...hod())': u64
-            375..376 'S': S
-            378..392 '|s| s.method()': |S| -> u64
-            379..380 's': S
-            382..383 's': S
-            382..392 's.method()': u64
-            403..405 'x2': u64
-            408..412 'foo2': fn foo2<S, u64, |S| -> u64>(|S| -> u64, S) -> u64
-            408..431 'foo2(|...(), S)': u64
-            413..427 '|s| s.method()': |S| -> u64
-            414..415 's': S
-            417..418 's': S
-            417..427 's.method()': u64
-            429..430 'S': S
-            441..443 'x3': u64
-            446..447 'S': S
-            446..471 'S.foo1...hod())': u64
-            453..454 'S': S
-            456..470 '|s| s.method()': |S| -> u64
-            457..458 's': S
-            460..461 's': S
-            460..470 's.method()': u64
-            481..483 'x4': u64
-            486..487 'S': S
-            486..511 'S.foo2...(), S)': u64
-            493..507 '|s| s.method()': |S| -> u64
-            494..495 's': S
-            497..498 's': S
-            497..507 's.method()': u64
-            509..510 'S': S
+            111..122 '{ loop {} }': U
+            113..120 'loop {}': !
+            118..120 '{}': ()
+            156..157 'f': F
+            162..163 'x': T
+            173..184 '{ loop {} }': U
+            175..182 'loop {}': !
+            180..182 '{}': ()
+            219..223 'self': S
+            271..275 'self': S
+            277..278 'x': T
+            283..284 'f': F
+            294..305 '{ loop {} }': U
+            296..303 'loop {}': !
+            301..303 '{}': ()
+            343..347 'self': S
+            349..350 'f': F
+            355..356 'x': T
+            366..377 '{ loop {} }': U
+            368..375 'loop {}': !
+            373..375 '{}': ()
+            391..550 '{     ... S); }': ()
+            401..403 'x1': u64
+            406..410 'foo1': fn foo1<S, u64, |S| -> u64>(S, |S| -> u64) -> u64
+            406..429 'foo1(S...hod())': u64
+            411..412 'S': S
+            414..428 '|s| s.method()': |S| -> u64
+            415..416 's': S
+            418..419 's': S
+            418..428 's.method()': u64
+            439..441 'x2': u64
+            444..448 'foo2': fn foo2<S, u64, |S| -> u64>(|S| -> u64, S) -> u64
+            444..467 'foo2(|...(), S)': u64
+            449..463 '|s| s.method()': |S| -> u64
+            450..451 's': S
+            453..454 's': S
+            453..463 's.method()': u64
+            465..466 'S': S
+            477..479 'x3': u64
+            482..483 'S': S
+            482..507 'S.foo1...hod())': u64
+            489..490 'S': S
+            492..506 '|s| s.method()': |S| -> u64
+            493..494 's': S
+            496..497 's': S
+            496..506 's.method()': u64
+            517..519 'x4': u64
+            522..523 'S': S
+            522..547 'S.foo2...(), S)': u64
+            529..543 '|s| s.method()': |S| -> u64
+            530..531 's': S
+            533..534 's': S
+            533..543 's.method()': u64
+            545..546 'S': S
         "#]],
     );
 }
@@ -2536,7 +2550,7 @@ fn test() {
 
 #[test]
 fn iterator_chain() {
-    check_infer(
+    check_infer_with_mismatches(
         r#"
         //- /main.rs
         #[lang = "fn_once"]
@@ -2939,7 +2953,7 @@ fn infer_closure_arg() {
 
 #[test]
 fn infer_fn_trait_arg() {
-    check_infer(
+    check_infer_with_mismatches(
         r#"
         //- /lib.rs deps:std
 
@@ -2986,7 +3000,8 @@ fn infer_fn_trait_arg() {
 
 #[test]
 fn infer_box_fn_arg() {
-    check_infer(
+    // The type mismatch is a bug
+    check_infer_with_mismatches(
         r#"
         //- /lib.rs deps:std
 
@@ -3025,7 +3040,7 @@ fn infer_box_fn_arg() {
         fn foo() {
             let s = Option::None;
             let f: Box<dyn FnOnce(&Option<i32>)> = box (|ps| {});
-            f(&s)
+            f(&s);
         }
         "#,
         expect![[r#"
@@ -3037,7 +3052,7 @@ fn infer_box_fn_arg() {
             406..417 '&self.inner': &*mut T
             407..411 'self': &Box<T>
             407..417 'self.inner': *mut T
-            478..575 '{     ...(&s) }': FnOnce::Output<dyn FnOnce(&Option<i32>), (&Option<i32>,)>
+            478..576 '{     ...&s); }': ()
             488..489 's': Option<i32>
             492..504 'Option::None': Option<i32>
             514..515 'f': Box<dyn FnOnce(&Option<i32>)>
@@ -3049,6 +3064,7 @@ fn infer_box_fn_arg() {
             568..573 'f(&s)': FnOnce::Output<dyn FnOnce(&Option<i32>), (&Option<i32>,)>
             570..572 '&s': &Option<i32>
             571..572 's': Option<i32>
+            549..562: expected Box<dyn FnOnce(&Option<i32>)>, got Box<|_| -> ()>
         "#]],
     );
 }
diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
index 232cf9cd0..4bd8ba303 100644
--- a/crates/hir_ty/src/traits/chalk.rs
+++ b/crates/hir_ty/src/traits/chalk.rs
@@ -429,7 +429,7 @@ pub(crate) fn trait_datum_query(
     let generic_params = generics(db.upcast(), trait_.into());
     let bound_vars = Substs::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
     let flags = rust_ir::TraitFlags {
-        auto: trait_data.auto,
+        auto: trait_data.is_auto,
         upstream: trait_.lookup(db.upcast()).container.krate() != krate,
         non_enumerable: true,
         coinductive: false, // only relevant for Chalk testing
diff --git a/crates/hir_ty/src/traits/chalk/interner.rs b/crates/hir_ty/src/traits/chalk/interner.rs
index 1dc3f497d..94e94a26d 100644
--- a/crates/hir_ty/src/traits/chalk/interner.rs
+++ b/crates/hir_ty/src/traits/chalk/interner.rs
@@ -5,6 +5,7 @@ use super::tls;
 use base_db::salsa::InternId;
 use chalk_ir::{GenericArg, Goal, GoalData};
 use hir_def::TypeAliasId;
+use smallvec::SmallVec;
 use std::{fmt, sync::Arc};
 
 #[derive(Debug, Copy, Clone, Hash, PartialOrd, Ord, PartialEq, Eq)]
@@ -33,7 +34,7 @@ impl chalk_ir::interner::Interner for Interner {
     type InternedGenericArg = chalk_ir::GenericArgData<Self>;
     type InternedGoal = Arc<GoalData<Self>>;
     type InternedGoals = Vec<Goal<Self>>;
-    type InternedSubstitution = Vec<GenericArg<Self>>;
+    type InternedSubstitution = SmallVec<[GenericArg<Self>; 2]>;
     type InternedProgramClause = Arc<chalk_ir::ProgramClauseData<Self>>;
     type InternedProgramClauses = Arc<[chalk_ir::ProgramClause<Self>]>;
     type InternedQuantifiedWhereClauses = Vec<chalk_ir::QuantifiedWhereClause<Self>>;
@@ -265,13 +266,13 @@ impl chalk_ir::interner::Interner for Interner {
     fn intern_substitution<E>(
         &self,
         data: impl IntoIterator<Item = Result<GenericArg<Self>, E>>,
-    ) -> Result<Vec<GenericArg<Self>>, E> {
+    ) -> Result<Self::InternedSubstitution, E> {
         data.into_iter().collect()
     }
 
     fn substitution_data<'a>(
         &self,
-        substitution: &'a Vec<GenericArg<Self>>,
+        substitution: &'a Self::InternedSubstitution,
     ) -> &'a [GenericArg<Self>] {
         substitution
     }
diff --git a/crates/ide/src/call_hierarchy.rs b/crates/ide/src/call_hierarchy.rs
index b848945d7..96021f677 100644
--- a/crates/ide/src/call_hierarchy.rs
+++ b/crates/ide/src/call_hierarchy.rs
@@ -53,10 +53,8 @@ pub(crate) fn incoming_calls(db: &RootDatabase, position: FilePosition) -> Optio
         for (r_range, _) in references {
             let token = file.token_at_offset(r_range.start()).next()?;
             let token = sema.descend_into_macros(token);
-            let syntax = token.parent();
-
             // This target is the containing function
-            if let Some(nav) = syntax.ancestors().find_map(|node| {
+            if let Some(nav) = token.ancestors().find_map(|node| {
                 let fn_ = ast::Fn::cast(node)?;
                 let def = sema.to_def(&fn_)?;
                 def.try_to_nav(sema.db)
@@ -77,12 +75,13 @@ pub(crate) fn outgoing_calls(db: &RootDatabase, position: FilePosition) -> Optio
     let file = file.syntax();
     let token = file.token_at_offset(position.offset).next()?;
     let token = sema.descend_into_macros(token);
-    let syntax = token.parent();
 
     let mut calls = CallLocations::default();
 
-    syntax
-        .descendants()
+    token
+        .parent()
+        .into_iter()
+        .flat_map(|it| it.descendants())
         .filter_map(|node| FnCallNode::with_node_exact(&node))
         .filter_map(|call_node| {
             let name_ref = call_node.name_ref()?;
diff --git a/crates/ide/src/display.rs b/crates/ide/src/display.rs
index bae9e40df..1f7b665c0 100644
--- a/crates/ide/src/display.rs
+++ b/crates/ide/src/display.rs
@@ -5,6 +5,5 @@ pub(crate) mod navigation_target;
 mod short_label;
 
 pub(crate) use navigation_target::{ToNav, TryToNav};
-pub(crate) use short_label::ShortLabel;
 
 pub(crate) use syntax::display::{function_declaration, macro_label};
diff --git a/crates/ide/src/display/navigation_target.rs b/crates/ide/src/display/navigation_target.rs
index 198243466..69c3751a1 100644
--- a/crates/ide/src/display/navigation_target.rs
+++ b/crates/ide/src/display/navigation_target.rs
@@ -3,7 +3,9 @@
 use std::fmt;
 
 use either::Either;
-use hir::{AssocItem, Documentation, FieldSource, HasAttrs, HasSource, InFile, ModuleSource};
+use hir::{
+    AssocItem, Documentation, FieldSource, HasAttrs, HasSource, HirDisplay, InFile, ModuleSource,
+};
 use ide_db::{
     base_db::{FileId, FileRange, SourceDatabase},
     symbol_index::FileSymbolKind,
@@ -98,7 +100,7 @@ impl NavigationTarget {
                 SymbolKind::Module,
             );
             res.docs = module.attrs(db).docs();
-            res.description = src.value.short_label();
+            res.description = Some(module.display(db).to_string());
             return res;
         }
         module.to_nav(db)
@@ -251,8 +253,8 @@ impl ToNavFromAst for hir::Trait {
 
 impl<D> TryToNav for D
 where
-    D: HasSource + ToNavFromAst + Copy + HasAttrs,
-    D::Ast: ast::NameOwner + ShortLabel,
+    D: HasSource + ToNavFromAst + Copy + HasAttrs + HirDisplay,
+    D::Ast: ast::NameOwner,
 {
     fn try_to_nav(&self, db: &RootDatabase) -> Option<NavigationTarget> {
         let src = self.source(db)?;
@@ -262,7 +264,7 @@ where
             D::KIND,
         );
         res.docs = self.docs(db);
-        res.description = src.value.short_label();
+        res.description = Some(self.display(db).to_string());
         Some(res)
     }
 }
@@ -317,7 +319,7 @@ impl TryToNav for hir::Field {
                 let mut res =
                     NavigationTarget::from_named(db, src.with_value(it), SymbolKind::Field);
                 res.docs = self.docs(db);
-                res.description = it.short_label();
+                res.description = Some(self.display(db).to_string());
                 res
             }
             FieldSource::Pos(it) => {
diff --git a/crates/ide/src/doc_links.rs b/crates/ide/src/doc_links.rs
index 7bdd3cca3..461e11060 100644
--- a/crates/ide/src/doc_links.rs
+++ b/crates/ide/src/doc_links.rs
@@ -279,7 +279,7 @@ pub(crate) fn external_docs(
     let token = pick_best(file.token_at_offset(position.offset))?;
     let token = sema.descend_into_macros(token);
 
-    let node = token.parent();
+    let node = token.parent()?;
     let definition = match_ast! {
         match node {
             ast::NameRef(name_ref) => NameRefClass::classify(&sema, &name_ref).map(|d| d.referenced(sema.db)),
diff --git a/crates/ide/src/extend_selection.rs b/crates/ide/src/extend_selection.rs
index b540d04fe..e187243cb 100644
--- a/crates/ide/src/extend_selection.rs
+++ b/crates/ide/src/extend_selection.rs
@@ -88,7 +88,7 @@ fn try_extend_selection(
                     return Some(range);
                 }
             }
-            token.parent()
+            token.parent()?
         }
         NodeOrToken::Node(node) => node,
     };
@@ -142,7 +142,8 @@ fn extend_tokens_from_range(
     let extended = {
         let fst_expanded = sema.descend_into_macros(first_token.clone());
         let lst_expanded = sema.descend_into_macros(last_token.clone());
-        let mut lca = algo::least_common_ancestor(&fst_expanded.parent(), &lst_expanded.parent())?;
+        let mut lca =
+            algo::least_common_ancestor(&fst_expanded.parent()?, &lst_expanded.parent()?)?;
         lca = shallowest_node(&lca);
         if lca.first_token() == Some(fst_expanded) && lca.last_token() == Some(lst_expanded) {
             lca = lca.parent()?;
@@ -151,9 +152,13 @@ fn extend_tokens_from_range(
     };
 
     // Compute parent node range
-    let validate = |token: &SyntaxToken| {
+    let validate = |token: &SyntaxToken| -> bool {
         let expanded = sema.descend_into_macros(token.clone());
-        algo::least_common_ancestor(&extended, &expanded.parent()).as_ref() == Some(&extended)
+        let parent = match expanded.parent() {
+            Some(it) => it,
+            None => return false,
+        };
+        algo::least_common_ancestor(&extended, &parent).as_ref() == Some(&extended)
     };
 
     // Find the first and last text range under expanded parent
diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs
index e8f31e4b1..6986477a5 100644
--- a/crates/ide/src/goto_definition.rs
+++ b/crates/ide/src/goto_definition.rs
@@ -30,7 +30,7 @@ pub(crate) fn goto_definition(
     let file = sema.parse(position.file_id).syntax().clone();
     let original_token = pick_best(file.token_at_offset(position.offset))?;
     let token = sema.descend_into_macros(original_token.clone());
-    let parent = token.parent();
+    let parent = token.parent()?;
     if let Some(comment) = ast::Comment::cast(token) {
         let nav = def_for_doc_comment(&sema, position, &comment)?.try_to_nav(db)?;
         return Some(RangeInfo::new(original_token.text_range(), vec![nav]));
@@ -63,7 +63,7 @@ fn def_for_doc_comment(
     position: FilePosition,
     doc_comment: &ast::Comment,
 ) -> Option<hir::ModuleDef> {
-    let parent = doc_comment.syntax().parent();
+    let parent = doc_comment.syntax().parent()?;
     let (link, ns) = extract_positioned_link_from_comment(position, doc_comment)?;
 
     let def = doc_owner_to_def(sema, parent)?;
diff --git a/crates/ide/src/goto_type_definition.rs b/crates/ide/src/goto_type_definition.rs
index 369a59820..2d38cb112 100644
--- a/crates/ide/src/goto_type_definition.rs
+++ b/crates/ide/src/goto_type_definition.rs
@@ -22,7 +22,7 @@ pub(crate) fn goto_type_definition(
     let token: SyntaxToken = pick_best(file.syntax().token_at_offset(position.offset))?;
     let token: SyntaxToken = sema.descend_into_macros(token);
 
-    let (ty, node) = sema.ancestors_with_macros(token.parent()).find_map(|node| {
+    let (ty, node) = sema.token_ancestors_with_macros(token).find_map(|node| {
         let ty = match_ast! {
             match node {
                 ast::Expr(it) => sema.type_of_expr(&it)?,
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index ea45086ce..8d45b4875 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -1,7 +1,7 @@
 use either::Either;
 use hir::{
-    Adt, AsAssocItem, AssocItemContainer, FieldSource, GenericParam, HasAttrs, HasSource,
-    HirDisplay, Module, ModuleDef, ModuleSource, Semantics,
+    Adt, AsAssocItem, AssocItemContainer, GenericParam, HasAttrs, HasSource, HirDisplay, Module,
+    ModuleDef, Semantics,
 };
 use ide_db::{
     base_db::SourceDatabase,
@@ -14,7 +14,7 @@ use stdx::format_to;
 use syntax::{ast, match_ast, AstNode, SyntaxKind::*, SyntaxToken, TokenAtOffset, T};
 
 use crate::{
-    display::{macro_label, ShortLabel, TryToNav},
+    display::{macro_label, TryToNav},
     doc_links::{remove_links, rewrite_links},
     markdown_remove::remove_markdown,
     markup::Markup,
@@ -92,7 +92,7 @@ pub(crate) fn hover(
 
     let mut res = HoverResult::default();
 
-    let node = token.parent();
+    let node = token.parent()?;
     let definition = match_ast! {
         match node {
             // we don't use NameClass::referenced_or_defined here as we do not want to resolve
@@ -335,34 +335,18 @@ fn hover_for_definition(
             let label = macro_label(&it.source(db)?.value);
             from_def_source_labeled(db, it, Some(label), mod_path)
         }
-        Definition::Field(def) => {
-            let src = def.source(db)?.value;
-            if let FieldSource::Named(it) = src {
-                from_def_source_labeled(db, def, it.short_label(), mod_path)
-            } else {
-                None
-            }
-        }
+        Definition::Field(def) => from_hir_fmt(db, def, mod_path),
         Definition::ModuleDef(it) => match it {
-            ModuleDef::Module(it) => from_def_source_labeled(
-                db,
-                it,
-                match it.definition_source(db).value {
-                    ModuleSource::Module(it) => it.short_label(),
-                    ModuleSource::SourceFile(it) => it.short_label(),
-                    ModuleSource::BlockExpr(it) => it.short_label(),
-                },
-                mod_path,
-            ),
-            ModuleDef::Function(it) => from_def_source(db, it, mod_path),
-            ModuleDef::Adt(Adt::Struct(it)) => from_def_source(db, it, mod_path),
-            ModuleDef::Adt(Adt::Union(it)) => from_def_source(db, it, mod_path),
-            ModuleDef::Adt(Adt::Enum(it)) => from_def_source(db, it, mod_path),
-            ModuleDef::Variant(it) => from_def_source(db, it, mod_path),
-            ModuleDef::Const(it) => from_def_source(db, it, mod_path),
-            ModuleDef::Static(it) => from_def_source(db, it, mod_path),
-            ModuleDef::Trait(it) => from_def_source(db, it, mod_path),
-            ModuleDef::TypeAlias(it) => from_def_source(db, it, mod_path),
+            ModuleDef::Module(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Function(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Adt(Adt::Struct(it)) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Adt(Adt::Union(it)) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Adt(Adt::Enum(it)) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Variant(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Const(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Static(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Trait(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::TypeAlias(it) => from_hir_fmt(db, it, mod_path),
             ModuleDef::BuiltinType(it) => famous_defs
                 .and_then(|fd| hover_for_builtin(fd, it))
                 .or_else(|| Some(Markup::fenced_block(&it.name()))),
@@ -370,26 +354,25 @@ fn hover_for_definition(
         Definition::Local(it) => hover_for_local(it, db),
         Definition::SelfType(impl_def) => {
             impl_def.target_ty(db).as_adt().and_then(|adt| match adt {
-                Adt::Struct(it) => from_def_source(db, it, mod_path),
-                Adt::Union(it) => from_def_source(db, it, mod_path),
-                Adt::Enum(it) => from_def_source(db, it, mod_path),
+                Adt::Struct(it) => from_hir_fmt(db, it, mod_path),
+                Adt::Union(it) => from_hir_fmt(db, it, mod_path),
+                Adt::Enum(it) => from_hir_fmt(db, it, mod_path),
             })
         }
         Definition::Label(it) => Some(Markup::fenced_block(&it.name(db))),
         Definition::GenericParam(it) => match it {
             GenericParam::TypeParam(it) => Some(Markup::fenced_block(&it.display(db))),
             GenericParam::LifetimeParam(it) => Some(Markup::fenced_block(&it.name(db))),
-            GenericParam::ConstParam(it) => from_def_source(db, it, None),
+            GenericParam::ConstParam(it) => Some(Markup::fenced_block(&it.display(db))),
         },
     };
 
-    fn from_def_source<A, D>(db: &RootDatabase, def: D, mod_path: Option<String>) -> Option<Markup>
+    fn from_hir_fmt<D>(db: &RootDatabase, def: D, mod_path: Option<String>) -> Option<Markup>
     where
-        D: HasSource<Ast = A> + HasAttrs + Copy,
-        A: ShortLabel,
+        D: HasAttrs + HirDisplay,
     {
-        let short_label = def.source(db)?.value.short_label();
-        from_def_source_labeled(db, def, short_label, mod_path)
+        let label = def.display(db).to_string();
+        from_def_source_labeled(db, def, Some(label), mod_path)
     }
 
     fn from_def_source_labeled<D>(
@@ -438,7 +421,7 @@ fn hover_for_keyword(
     if !token.kind().is_keyword() {
         return None;
     }
-    let famous_defs = FamousDefs(&sema, sema.scope(&token.parent()).krate());
+    let famous_defs = FamousDefs(&sema, sema.scope(&token.parent()?).krate());
     // std exposes {}_keyword modules with docstrings on the root to document keywords
     let keyword_mod = format!("{}_keyword", token.text());
     let doc_owner = find_std_module(&famous_defs, &keyword_mod)?;
@@ -670,7 +653,9 @@ fn main() { let foo_test = fo$0o(); }
                 ```
 
                 ```rust
-                pub fn foo<'a, T: AsRef<str>>(b: &'a T) -> &'a str
+                pub fn foo<'a, T>(b: &'a T) -> &'a str
+                where
+                    T: AsRef<str>,
                 ```
             "#]],
         );
@@ -878,7 +863,7 @@ fn main() { So$0me(12); }
                 ```
 
                 ```rust
-                Some
+                Some(T)
                 ```
             "#]],
         );
@@ -944,7 +929,7 @@ fn main() {
                 ```
 
                 ```rust
-                Some
+                Some(T)
                 ```
 
                 ---
@@ -1441,13 +1426,14 @@ fn bar() { fo$0o(); }
                 ```
             "#]],
         );
+        // Top level `pub(crate)` will be displayed as no visibility.
         check(
-            r#"pub(crate) async unsafe extern "C" fn foo$0() {}"#,
+            r#"mod m { pub(crate) async unsafe extern "C" fn foo$0() {} }"#,
             expect![[r#"
                 *foo*
 
                 ```rust
-                test
+                test::m
                 ```
 
                 ```rust
@@ -1489,11 +1475,18 @@ extern crate st$0d;
 //! abc123
             "#,
             expect![[r#"
-            *std*
-            Standard library for this test
+                *std*
+
+                ```rust
+                extern crate std
+                ```
 
-            Printed?
-            abc123
+                ---
+
+                Standard library for this test
+
+                Printed?
+                abc123
             "#]],
         );
         check(
@@ -1507,11 +1500,18 @@ extern crate std as ab$0c;
 //! abc123
             "#,
             expect![[r#"
-            *abc*
-            Standard library for this test
+                *abc*
+
+                ```rust
+                extern crate std
+                ```
+
+                ---
 
-            Printed?
-            abc123
+                Standard library for this test
+
+                Printed?
+                abc123
             "#]],
         );
     }
@@ -2021,7 +2021,7 @@ enum E {
                 ```
 
                 ```rust
-                V
+                V { field: i32 }
                 ```
 
                 ---
@@ -2417,7 +2417,7 @@ fn main() { let s$0t = S{ f1:Arg(0) }; }
                                     focus_range: 24..25,
                                     name: "S",
                                     kind: Struct,
-                                    description: "struct S",
+                                    description: "struct S<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2463,7 +2463,7 @@ fn main() { let s$0t = S{ f1: S{ f1: Arg(0) } }; }
                                     focus_range: 24..25,
                                     name: "S",
                                     kind: Struct,
-                                    description: "struct S",
+                                    description: "struct S<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2605,7 +2605,7 @@ fn main() { let s$0t = foo(); }
                                     focus_range: 6..9,
                                     name: "Foo",
                                     kind: Trait,
-                                    description: "trait Foo",
+                                    description: "trait Foo<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2702,7 +2702,7 @@ fn main() { let s$0t = foo(); }
                                     focus_range: 6..9,
                                     name: "Foo",
                                     kind: Trait,
-                                    description: "trait Foo",
+                                    description: "trait Foo<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2715,7 +2715,7 @@ fn main() { let s$0t = foo(); }
                                     focus_range: 22..25,
                                     name: "Bar",
                                     kind: Trait,
-                                    description: "trait Bar",
+                                    description: "trait Bar<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2819,7 +2819,7 @@ fn foo(ar$0g: &impl Foo + Bar<S>) {}
                                     focus_range: 19..22,
                                     name: "Bar",
                                     kind: Trait,
-                                    description: "trait Bar",
+                                    description: "trait Bar<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2916,7 +2916,7 @@ fn foo(ar$0g: &impl Foo<S>) {}
                                     focus_range: 6..9,
                                     name: "Foo",
                                     kind: Trait,
-                                    description: "trait Foo",
+                                    description: "trait Foo<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2966,7 +2966,7 @@ fn main() { let s$0t = foo(); }
                                     focus_range: 49..50,
                                     name: "B",
                                     kind: Struct,
-                                    description: "struct B",
+                                    description: "struct B<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -3042,7 +3042,7 @@ fn foo(ar$0g: &dyn Foo<S>) {}
                                     focus_range: 6..9,
                                     name: "Foo",
                                     kind: Trait,
-                                    description: "trait Foo",
+                                    description: "trait Foo<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -3090,7 +3090,7 @@ fn foo(a$0rg: &impl ImplTrait<B<dyn DynTrait<B<S>>>>) {}
                                     focus_range: 6..15,
                                     name: "ImplTrait",
                                     kind: Trait,
-                                    description: "trait ImplTrait",
+                                    description: "trait ImplTrait<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -3103,7 +3103,7 @@ fn foo(a$0rg: &impl ImplTrait<B<dyn DynTrait<B<S>>>>) {}
                                     focus_range: 50..51,
                                     name: "B",
                                     kind: Struct,
-                                    description: "struct B",
+                                    description: "struct B<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -3116,7 +3116,7 @@ fn foo(a$0rg: &impl ImplTrait<B<dyn DynTrait<B<S>>>>) {}
                                     focus_range: 28..36,
                                     name: "DynTrait",
                                     kind: Trait,
-                                    description: "trait DynTrait",
+                                    description: "trait DynTrait<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -3582,6 +3582,17 @@ mod foo$0;
 "#,
             expect![[r#"
                 *foo*
+
+                ```rust
+                test
+                ```
+
+                ```rust
+                mod foo
+                ```
+
+                ---
+
                 For the horde!
             "#]],
         );
@@ -3606,7 +3617,7 @@ use foo::bar::{self$0};
                 ```
 
                 ```rust
-                pub mod bar
+                mod bar
                 ```
 
                 ---
@@ -3657,4 +3668,43 @@ cosnt _: &str$0 = ""; }"#;